WO2017080980A1

WO2017080980A1 - Dihydropyrrolopyrazinone derivatives useful in the treatment of cancer

Info

Publication number: WO2017080980A1
Application number: PCT/EP2016/076933
Authority: WO
Inventors: Richard Andrew Ward; Clifford David Jones; James Lyman FERON
Original assignee: Astrazeneca Ab
Priority date: 2015-11-09
Filing date: 2016-11-08
Publication date: 2017-05-18

Abstract

The invention concerns compounds of Formula (I) or pharmaceutically-acceptable salts thereof, wherein R¹ has any of the meanings hereinbefore in the description; processes for their preparation, pharmaceutical compositions containing them and their use in the treatment of cancer.

Description

DIHYDROPYRROLOPYRAZINONE DERIVATIVES USEFUL IN THE TREATMENT OF CANCER

The invention relates to certain dihydropyrrolopyrazinone derivatives and pharmaceutically-acceptable salts thereof that selectively inhibit ERK and possess anti-cancer activity. The invention also relates to use of said dihydropyrrolopyrazinone derivatives and pharmaceutically-acceptable salts thereof in methods of treatment of the human or animal body, for example in prevention or treatment of cancer. The invention also relates to processes and intermediate compounds involved in the preparation of said dihydropyrrolopyrazinone derivatives and to pharmaceutical compositions containing said dihydropyrrolopyrazinone derivatives and pharmaceutically-acceptable salts thereof.

Protein kinases play a key regulatory role in almost every aspect of cell biology. The mammalian MAP kinases consist of cytoplasmic protein serine/threonine kinases that participate in the transduction of cellular signals from the plasma membrane to the nucleus. There are multiple MAPK signalling cascades each consisting of 3 components: a MAPK kinase (MAP3K), a MAPK kinase (MAP2K) and a MAPK. The activated MAP kinases phosphorylate numerous substrates including other protein kinases, protein phosphatases, transcription factors and other functional proteins. The RAS-RAF-MEK-ERK signalling cascade participates in the regulation of cell cycle progression, cell proliferation, survival, metabolism and transcription.

ERKl and ERK2 are ubiquitously expressed MAPK kinases that participate in the RAS-RAF-MEK-ERK signalling cascade, which both contain unique N- and C-terminal extensions that provide signalling specificity, in addition to a 31 -amino-acid-residue insertion within the kinase domain that provide additional functional specificity. ERKl and ERK2 are activated in a wide variety of cell types by mitogenic and other stimuli, resulting in activation of multiple iso forms of RAS (HRAS, NRAS and KRAS). Activation of RAS leads to recruitment and activation of RAF iso forms (ARAF, BRAF and CRAF) and subsequent activation of MEK1 and MEK2, dual-specificity protein kinases that mediate the phosphorylation of tyrosine and threonine of ERKl and ERK2. ERKl and ERK2 have a large number of identified cytoplasmic and nuclear substrates (reference Yoon S, Seger R. The extracellular signal-regulated kinase: multiple substrates regulate diverse cellular functions; Growth Factors 2006, 24, 21-44). The RAS-RAF-MEK-ERK signalling cascade is deregulated in a variety of diseases including brain injury, cancer, cardiac hypertrophy, diabetes and inflammation. Specifically in cancer, mutations in KRAS occur in approximately 58% of pancreatic, 33% of colorectal and 31% of biliary cancers, and NRAS mutations in 18% of melanomas. Oncogenic mutations in RAS result in elevated ERK activity across multiple tumours. In addition, BRAF mutations occur in approximately 40-60% of melanomas, 40% of thyroid cancers and 20% of colorectal cancers (reference Vakiani E, Solit DB. KRAS and BRAF; drug targets and predictive biomarkers; Journal of Pathology 2011 , 223, 219-29). These observations indicate that the RAS-RAF-MEK-ERK signalling cascade is an attractive pathway for anti-cancer therapies across a broad range of human tumours.

We have found a series of chemical compounds which have selectivity for inhibition of ERK over other kinases on the same signalling cascade.

Where inhibition of ERK is referred to herein, it should be understood to mean inhibition of ERK1 and/or ERK2, particularly ERK2.

According to one aspect there is provided a compound of the Formula (I):

(I)

wherein:

R¹ is pyrimidinyl, optionally substituted on one ring carbon atom by methyl provided that no more than 1 ring carbon atom is substituted; or

R¹ is triazolyl, optionally substituted on one ring carbon atom by methyl provided that no more than 1 ring carbon atom is substituted, and optionally substituted on one ring nitrogen by methyl provided that no more than 1 ring nitrogen atom is substituted;

or a pharmaceutically-acceptable salt thereof.

In one embodiment there is provided a compound of Formula (I) as defined above.

In one embodiment there is provided a pharmaceutically-acceptable salt of a compound of Formula (I). The term "optionally substituted" will be understood to mean "substituted or unsubstituted".

In one aspect, R¹ is selected from optionally substituted pyrimidinyl, optionally substituted 1,2,4-triazolyl and optionally substituted 1,2,3-triazolyl; wherein optional substituents are as described hereinbefore;

or a pharmaceutically-acceptable salt thereof.

In one aspect, R¹ is optionally substituted pyrimidinyl; wherein optional substituents are herein described.

In one aspect, R¹ is optionally substituted triazolyl; wherein optional substituents are herein described.

In one aspect, R¹ is optionally substituted 1,2,4-triazolyl; wherein optional substituents are herein described.

In one aspect, R¹ is optionally substituted 1,2,3-triazolyl; wherein optional substituents are herein described.

In one aspect, R¹ is selected from pyrimidin-4-yl, 5-methylpyrimidin-4-yl, 6- methylpyrimidin-4-yl, 2-methylpyrimidin-4-yl, pyrimidin-2-yl, 4-methylpyrimidin-2-yl, 5- methylpyrimidin-2-yl, pyrimidin-5-yl, 4-methylpyrimidin-5-yl, 2-methylpyrimidin-5-yl, l,2,4-triazol-3-yl, 1 -methyl- l,2,4-triazol-5-yl, 4-methyl-l,2,4-triazol-3-yl, 1 -methyl- 1,2,4- triazol-3-yl, 5-methyl-l,2,4-triazol-3-yl, l,3-dimethyl-l,2,4-triazol-5-yl, 4,5-dimethyl- l,2,4-triazol-3-yl, l,5-dimethyl-l,2,4-triazol-3-yl, l,2,3-triazol-5-yl, 4-methyl-l,2,3- triazol-5-yl, l-methyl-l,2,3-triazol-5-yl, 2-methyl-l,2,3-triazol-4-yl, l-methyl-1,2,3- triazol-4-yl, l,5-dimethyl-l,2,3-triazol-4-yl, 2,5-dimethyl-l,2,3-triazoy-4-yl, and 1,4- dimethyl- 1 ,2,3-triazol-5-yl.

In one aspect, R¹ is selected from 6-methylpyrimidin-4-yl, 2-methylpyrimidin-4-yl, l,3-dimethyl-l,2,4-triazol-5-yl, 1 -methyl- 1, 2, 3-triazol-5-yl, 2-methyl-l,2,3-triazol-4-yl and 1 -methyl- 1 ,2,3 -triazol-4-yl.

In one aspect, R¹ is selected from 2-methylpyrimidin-4-yl and2-methyl-l,2,3- triazol-4-yl.

In one aspect, R¹ is 6-methylpyrimidin-4-yl.

In one aspect, R¹ is 2-methylpyrimidin-4-yl.

In one aspect, R¹ is l,3-dimethyl-l,2,4-triazol-5-yl.

In one aspect, R¹ is 1 -methyl- 1, 2, 3-triazol-5-yl. In one aspect, R¹ is 2-methyl-l,2,3-triazol-4-yl.

In one aspect, R¹ is 1 -methyl- 1, 2, 3-triazol-4-yl.

In a further aspect, there is provided a compound of formula (I) or a

pharmaceutically-acceptable salt thereof, wherein:

R¹ is pyrimidinyl, optionally substituted on one ring carbon atom by methyl provided that no more than 1 ring carbon atom is substituted;

R¹ is 1,2,4-triazolyl, optionally substituted on one ring carbon atom by methyl provided that no more than 1 ring carbon atom is substituted, and optionally substituted on one ring nitrogen by methyl provided that no more than 1 ring nitrogen atom is substituted; or R¹ is 1,2,3-triazolyl, optionally substituted on one ring carbon atom by methyl provided that no more than 1 ring carbon atom is substituted, and optionally substituted on one ring nitrogen by methyl provided that no more than 1 ring nitrogen atom is substituted.

In a further aspect, there is provided a compound of formula (I) or a

pharmaceutically-acceptable salt thereof, wherein:

R¹ is pyrimidinyl, optionally substituted on one ring carbon atom by methyl provided that no more than 1 ring carbon atom is substituted.

In a further aspect, there is provided a compound of formula (I) or a

pharmaceutically-acceptable salt thereof, wherein:

R¹ is 1,2,4-triazolyl, optionally substituted on one ring carbon atom by methyl provided that no more than 1 ring carbon atom is substituted, and optionally substituted on one ring nitrogen by methyl provided that no more than 1 ring nitrogen atom is substituted.

In a further aspect, there is provided a compound of formula (I) or a

pharmaceutically-acceptable salt thereof, wherein:

R¹ is 1,2,3-triazolyl, optionally substituted on one ring carbon atom by methyl provided that no more than 1 ring carbon atom is substituted, and optionally substituted on one ring nitrogen by methyl provided that no more than 1 ring nitrogen atom is substituted.

In a further aspect, there is provided a compound of formula (I) or a

pharmaceutically-acceptable salt thereof, wherein:

R¹ is selected from pyrimidin-4-yl, 5-methylpyrimidin-4-yl, 6-methylpyrimidin-4-yl, 2- methylpyrimidin-4-yl, pyrimidin-2-yl, 4-methylpyrimidin-2-yl, 5-methylpyrimidin-2-yl, pyrimidin-5-yl, 4-methylpyrimidin-5-yl, 2-methylpyrimidin-5-yl, l,2,4-triazol-3-yl, 1- methyl-l,2,4-triazol-5-yl, 4-methyl-l,2,4-triazol-3-yl, l-methyl-l,2,4-triazol-3-yl, 5- methyl- 1 ,2,4-triazol-3-yl, 1 ,3-dimethyl- 1 ,2,4-triazol-5-yl, 4,5-dimethyl- 1 ,2,4-triazol-3-yl, 1,5-dimethyl- l,2,4-triazol-3-yl, l,2,3-triazol-5-yl, 4-methyl-l,2,3-triazol-5-yl, 1-methyl- l,2,3-triazol-5-yl, 2-methyl-l,2,3-triazol-4-yl, 1 -methyl- 1, 2,3 -triazol-4-yl, 1,5-dimethyl- l,2,3-triazol-4-yl, 2,5-dimethyl-l,2,3-triazoy-4-yl and l,4-dimethyl-l,2,3-triazol-5-yl.

In a further aspect, there is provided a compound of formula (I) or a

pharmaceutically-acceptable salt thereof, wherein:

R¹ is selected from 6-methylpyrimidin-4-yl, 2-methylpyrimidin-4-yl, 1,3 -dimethyl- 1,2,4- triazol-5-yl, l-methyl-l,2,3-triazol-5-yl, 2-methyl-l,2,3-triazol-4-yl and 1 -methyl- 1,2,3 - triazol-4-yl.

In a further aspect, there is provided a compound of formula (I) or a

pharmaceutically-acceptable salt thereof, wherein:

R¹ is selected from 2-methylpyrimidin-4-yl and 2-methyl-l,2,3-triazol-4-yl.

In a further aspect, there is provided a compound of formula (I) or a

pharmaceutically-acceptable salt thereof, wherein:

R¹ is 6-methylpyrimidin-4-yl.

In a further aspect, there is provided a compound of formula (I) or a

pharmaceutically-acceptable salt thereof, wherein:

R¹ is 2-methylpyrimidin-4-yl.

In a further aspect, there is provided a compound of formula (I) or a

pharmaceutically-acceptable salt thereof, wherein:

R¹ is l,3-dimethyl-l,2,4-triazol-5-yl.

In a further aspect, there is provided a compound of formula (I) or a

pharmaceutically-acceptable salt thereof, wherein:

R¹ is 2-methyl-l,2,3-triazol-4-yl.

In a further aspect, there is provided a compound of formula (I) or a

pharmaceutically-acceptable salt thereof, wherein:

R¹ is 1 -methyl- 1, 2, 3-triazol-5-yl.

In a further aspect, there is provided a compound of formula (I) or a

pharmaceutically-acceptable salt thereof, wherein:

R¹ is 1 -methyl- 1, 2,3 -triazol-4-yl.

In a further aspect, there is provided any one or more of the specific examples or a pharmaceutically-acceptable salt thereof. In a further aspect, there is provided the specific examples described herein or a pharmaceutically-acceptable salt thereof, wherein any one or more of the examples is excluded. In a further aspect, there is provided a compound selected from:

(5)-3-methyl-7-(5-methyl-2-((l-methyl-lH-pyrazol-5-yl)amino)pyridin-4-yl)-2-((6- methylpyrimidin-4-yl)methyl)-3 ,4-dihydropyrrolo [ 1 ,2-a]pyrazin- 1 (2H)-one;

(5)-3-methyl-7-(5-methyl-2-((l-methyl-lH-pyrazol-5-yl)amino)pyridin-4-yl)-2-((2- methylpyrimidin-4-yl)methyl)-3 ,4-dihydropyrrolo [ 1 ,2-a]pyrazin- 1 (2H)-one;

(5)-2-((l,3-dimethyl-lH-l,2,4-triazol-5-yl)methyl)-3-methyl-7-(5-methyl-2-((l-methyl- lH-pyrazol-5-yl)amino)pyridin-4-yl)-3,4-dihydropyrrolo[l,2-a]pyrazin-l(2H)-one;

(5)-3-Methyl-7-(5-methyl-2-((l-methyl-lH-pyrazol-5-yl)amino)pyridin-4-yl)-2-((2- methyl-2H-l,2,3-triazol-4-yl)methyl)-3,4-dihydropyrrolo[l,2-a]pyrazin-l(2H)-one; (5)-3-methyl-2-((l-methyl-lH-l,2,3-triazol-5-yl)methyl)-7-(5-methyl-2-((l-methyl-lH- pyrazol-5-yl)amino)pyridin-4-yl)-3,4-dihydropyrrolo[l,2-a]pyrazin-l(2H)-one; and (5)-3-methyl-2-((l-methyl-lH-l,2,3-triazol-4-yl)methyl)-7-(5-methyl-2-((l-methyl-lH- pyrazol-5-yl)amino)pyridin-4-yl)-3,4-dihydropyrrolo[l,2-a]pyrazin-l(2H)-one; or a pharmaceutically-acceptable salt thereof.

In a further aspect, there is provided a compound selected from:

(5)-3-methyl-7-(5-methyl-2-((l-methyl-lH-pyrazol-5-yl)amino)pyridin-4-yl)-2-((2- methylpyrimidin-4-yl)methyl)-3 ,4-dihydropyrrolo [ 1 ,2-a]pyrazin- 1 (2H)-one; and

(5)-3-Methyl-7-(5-methyl-2-((l-methyl-lH-pyrazol-5-yl)amino)pyridin-4-yl)-2-((2- methyl-2H-l,2,3-triazol-4-yl)methyl)-3,4-dihydropyrrolo[l,2-a]pyrazin-l(2H)-one; or a pharmaceutically-acceptable salt thereof.

In a further aspect, there is provided (5)-3-methyl-7-(5-methyl-2-((l-methyl-lH- pyrazol-5-yl)amino)pyridin-4-yl)-2-((6-methylpyrimidin-4-yl)methyl)-3,4- dihydropyrrolo[l,2-a]pyrazin-l(2H)-one; or a pharmaceutically-acceptable salt thereof.

In a further aspect, there is provided (5)-3-methyl-7-(5-methyl-2-((l-methyl-lH- pyrazol-5-yl)amino)pyridin-4-yl)-2-((2-methylpyrimidin-4-yl)methyl)-3,4- dihydropyrrolo[l,2-a]pyrazin-l(2H)-one; or a pharmaceutically-acceptable salt thereof.

In a further aspect, there is provided (5)-2-((l,3-dimethyl-lH-l,2,4-triazol-5- yl)methyl)-3-methyl-7-(5-methyl-2-((l -methyl- lH-pyrazol-5-yl)amino)pyridin-4-yl)-3,4- dihydropyrrolo[l,2-a]pyrazin-l(2H)-one; or a pharmaceutically-acceptable salt thereof. In a further aspect, there is provided (5)-3-Methyl-7-(5-methyl-2-((l-methyl-lH- pyrazol-5-yl)amino)pyridin-4-yl)-2-((2-methyl-2H-l,2,3-triazol-4-yl)methyl)-3,4- dihydropyrrolo[l,2-a]pyrazin-l(2H)-one; or a pharmaceutically-acceptable salt thereof.

In a further aspect, there is provided (S)-3-methyl-2-((l-methyl-lH-l,2,3-triazol-5- yl)methyl)-7-(5 -methyl -2-(( 1 -methyl- 1 H-pyrazol-5 -yl)amino)pyridin-4-yl)-3 , 4- dihydropyrrolo[l,2-a]pyrazin-l(2H)-one; or a pharmaceutically-acceptable salt thereof.

In a further aspect, there is provided (5)-3-methyl-2-((l-methyl-lH-l,2,3-triazol-4- yl)methyl)-7-(5 -methyl -2-(( 1 -methyl- 1 H-pyrazol-5 -yl)amino)pyridin-4-yl)-3 , 4- dihydropyrrolo[l,2-a]pyrazin-l(2H)-one; or a pharmaceutically-acceptable salt thereof.

The compounds of Formula (I) have one chiral centre and it will be recognised that the compound of Formula (I) may be prepared, isolated and/or supplied with or without the presence, in addition, of one or more of the other 2 possible enantiomeric isomers of the compound of Formula (I) in any relative proportions. The preparation of enantioenriched/ enantiopure compounds may be carried out by standard techniques of organic chemistry that are well known in the art, for example by synthesis from enantioenriched or enantiopure starting materials, use of an appropriate enantioenriched or enantiopure catalyst during synthesis, and/or by resolution of a racemic or partially enriched mixture of stereoisomers, for example via chiral chromatography.

For use in a pharmaceutical context it may be preferable to provide the compound of Formula (I) or pharmaceutically-acceptable salt thereof without large amounts of the other stereoisomeric forms being present.

In a further embodiment there is provided a composition comprising a compound of Formula (I) or a pharmaceutically-acceptable salt thereof, optionally together with one or more of the other stereoisomeric forms of the compound of Formula (I) or

pharmaceutically-acceptable salt thereof, wherein the compound of Formula (I) or pharmaceutically-acceptable salt thereof is present within the composition with an enantiomeric excess (%ee) of > 90%.

In a further embodiment the %ee in the above-mentioned composition is > 95%.

In a further embodiment the %ee in the above-mentioned composition is > 98%.

In a further embodiment the %ee in the above-mentioned composition is > 99%. In a further embodiment there is provided a pharmaceutical composition which comprises a compound of the Formula (I) or a pharmaceutically-acceptable salt thereof, in association with a pharmaceutically-acceptable diluent or carrier.

In one embodiment there is provided a pharmaceutical composition which comprises a compound of the Formula (I) or a pharmaceutically-acceptable salt thereof, in association with a pharmaceutically-acceptable diluent or carrier, optionally further comprising one or more of the other stereoisomeric forms of the compound of Formula (I) or pharmaceutically-acceptable salt thereof, wherein the compound of Formula (I) or pharmaceutically-acceptable salt thereof is present within the composition with an enantiomeric excess (%ee) of > 90%.

In a further embodiment the %ee in the above-mentioned composition is > 95%.

In a further embodiment the %ee in the above-mentioned composition is > 98%.

In a further embodiment the %ee in the above-mentioned composition is > 99%.

The compounds of Formula (I) and pharmaceutically-acceptable salts thereof may prepared, used or supplied in amorphous form, crystalline form, or semicrystalline form and any given compound of Formula (I) or pharmaceutically-acceptable salt thereof may be capable of being formed into more than one crystalline / polymorphic form, including hydrated (e.g. hemi-hydrate, a mono-hydrate, a di-hydrate, a tri-hydrate or other stoichiometry of hydrate) and/or solvated forms. It is to be understood that the present invention encompasses any and all such solid forms of the compound of Formula (I) and pharmaceutically-acceptable salts thereof.

In further embodiments there is provided a compound of Formula (I), which is obtainable by the methods described in the 'Examples' section hereinafter.

The present invention is intended to include all isotopes of atoms occurring in the present compounds. Isotopes will be understood to include those atoms having the same atomic number but different mass numbers. For example, isotopes of hydrogen include tritium and deuterium. Isotopes of carbon include ¹³C and ¹⁴C.

A suitable pharmaceutically-acceptable salt of a compound of the Formula (I) is, for example, an acid addition salt.

A further suitable pharmaceutically-acceptable salt of a compound of the Formula (I) is, for example, a salt formed within the human or animal body after administration of a compound of the Formula (I) to said human or animal body. A suitable pharmaceutically-acceptable salt of a compound of the Formula (I) may also be, for example, an acid-addition salt of a compound of the Formula (I), for example an acid-addition salt with a inorganic or organic acid such as hydrochloric acid, hydrobromic acid, sulphuric acid or trifluoroacetic acid. Pharmaceutically-acceptable salts of a compound of the Formula (I) may also be an acid-addition salt with an acid such as one of the following: acetic acid, adipic acid, benzene sulfonic acid, benzoic acid, cinnamic acid, citric acid, D,L-lactic acid, ethane disulfonic acid, ethane sulfonic acid, fumaric acid, L-tartaric acid, maleic acid, malic acid, malonic acid, methane sulfonic acid, napadisylic acid, phosphoric acid, saccharin, succinic acid or toluene sulfonic acid (such as /?-toluenesulfonic acid).

The compound of Formula (I) or pharmaceutically-acceptable salt thereof may be prepared as a co-crystal solid form. It is to be understood that a pharmaceutically- acceptable co-crystal of a compound of the Formula (I) or pharmaceutically-acceptable salts thereof, form an aspect of the present invention.

It is to be understood that a suitable pharmaceutically-acceptable pro-drug of a compound of the Formula (I) also forms an aspect of the present invention. Accordingly, the compounds of the invention may be administered in the form of a pro-drug, which is a compound that is broken down in the human or animal body to release a compound of the invention. A pro-drug may be used to alter the physical properties and/or the

pharmacokinetic properties of a compound of the invention. A pro-drug can be formed when the compound of the invention contains a suitable group or substituent to which a property-modifying group can be attached. Examples of pro-drugs include in-vivo cleavable ester or amide derivatives that may be formed at the carboxy group in a compound of the Formula (I).

Accordingly, one aspect of the present invention includes those compounds of Formula (I) as defined hereinbefore when made available by organic synthesis and when made available within the human or animal body by way of cleavage of a pro-drug thereof. Accordingly, the present invention includes those compounds of the Formula (I) that are produced by organic synthetic means and also such compounds that are produced in the human or animal body by way of metabolism of a precursor compound, that is a compound of the Formula (I) may be a synthetically-produced compound or a metabolically- produced compound. A suitable pharmaceutically-acceptable pro-drug of a compound of the Formula (I) is one that is based on reasonable medical judgement as being suitable for administration to the human or animal body without undesirable pharmacological activities and without undue toxicity.

Various forms of pro-drug have been described, for example in the following documents :- a) Methods in Enzymology, Vol. 42, p. 309-396, edited by K. Widder, et al.

(Academic Press, 1985);

b) Design of Pro-drugs, edited by H. Bundgaard, (Elsevier, 1985);

c) A Textbook of Drug Design and Development, edited by Krogsgaard-Larsen and H. Bundgaard, Chapter 5 "Design and Application of Pro-drugs", by H. Bundgaard p. 113- 191 (1991);

d) H. Bundgaard, Advanced Drug Delivery Reviews, 8, 1-38 (1992);

e) H. Bundgaard, et al., Journal of Pharmaceutical Sciences, 77, 285 (1988);

f) N. Kakeya, et al, Chem. Pharm. Bull, 32, 692 (1984);

g) T. Higuchi and V. Stella, "Pro-Drugs as Novel Delivery Systems", A.C.S.

Symposium Series, Volume 14; and

h) E. Roche (editor), "Bioreversible Carriers in Drug Design", Pergamon Press, 1987.

A suitable pharmaceutically-acceptable pro-drug of a compound of the Formula (I) that possesses a carboxy group is, for example, an in- vivo cleavable ester thereof. An in- vivo cleavable ester of a compound of the Formula (I) containing a carboxy group is, for example, a pharmaceutically-acceptable ester which is cleaved in the human or animal body to produce the parent acid. Suitable pharmaceutically-acceptable esters for a carboxy group include (l-6C)alkyl esters such as methyl, ethyl and tert- vXy\, (l-6C)alkoxymethyl esters such as methoxymethyl esters, (l-6C)alkanoyloxymethyl esters such as

pivaloyloxymethyl esters, 3-phthalidyl esters, (3-8C)cycloalkylcarbonyloxy-(l-6C)alkyl esters such as cyclopentylcarbonyloxymethyl and 1 -cyclohexylcarbonyloxyethyl esters, 2-oxo-l,3-dioxolenylmethyl esters such as 5-methyl-2-oxo-l,3-dioxolen-4-ylmethyl esters and (l-6C)alkoxycarbonyloxy-(l-6C)alkyl esters such as methoxycarbonyloxymethyl and 1 -methoxycarbonyloxy ethyl esters.

A suitable pharmaceutically-acceptable pro-drug of a compound of the Formula (I) which have a carboxy group is for example an in-vivo cleavable amide such as a N-Ci-ealkyl and N,N-di-(Ci_6alkyl)amide such as N-methyl, N-ethyl, N-propyl, N,N- dimethyl, N-ethyl-N-methyl or N,N-diethylamide.

The in-vivo effects of a compound of the Formula (I) may be exerted in part by one or more metabolites that are formed within the human or animal body after administration of a compound of the Formula (I). As stated hereinbefore, the in-vivo effects of a compound of the Formula (I) may also be exerted by way of metabolism of a precursor compound (a pro-drug).

For the avoidance of doubt it is to be understood that where in this specification a group is qualified by 'hereinbefore defined' or 'defined herein' the said group

encompasses the first occurring and broadest definition as well as each and all of the alternative definitions for that group.

Another aspect of the present disclosure provides a process for preparing a compound of the Formula (I), or a pharmaceutically-acceptable salt thereof. A suitable process is illustrated by the following representative process variants in which, unless otherwise stated R¹ has any of the meanings defined hereinbefore. Necessary starting materials may be obtained by standard procedures of organic chemistry or are

commercially available. The preparation of such starting materials is described in conjunction with the following representative process variants and within the

accompanying Examples. Alternatively, necessary starting materials are obtainable by analogous procedures to those illustrated which are within the ordinary skill of an organic chemist.

(ID 0

A compound of formula (I) may be prepared from a compound of formula (II), wherein L¹ is a suitable leaving group (such as halogen, or -S0₂Me, etc), by reaction with a compound of formula (VII), wherein P¹ is hydrogen, with a Pd catalyst and phosphine ligand with a suitable base (e.g. CS2CO3) in a suitable solvent (such as dioxane), under conditions of ambient or elevated temperatures (such as achieved by heating or by microwave irradiation).

It will be appreciated that a compound of formula (I) may be transformed into another compound of formula (I) using conditions well known in the art.

Compounds of formula (VII) are either commercially available or well known in the art.

A compound of formula (II) may be prepared from a compound of formula (III), wherein L¹ is a suitable leaving group (such as CI or -S0₂Me), by reaction with a compound of formula (VIII) wherein L² is a suitable leaving group (such as halogen, or - OS0₂Me, -Tos, etc), in the presence of a suitable base (such as sodium hydride or K2CO3) and a suitable solvent (such as N,N-dimethylformamide).

Compounds of formula (VIII) are either commercially available or well known in the art.

Alternatively compounds of formula (II) may be prepared from compounds of formula (IV), wherein R² is an alkyl group (such as methyl or ethyl), by the reaction with compounds of the formula (IX) in the presence of suitable reducing reagent (such as NaB(OAc)₃H) and a suitable solvent (such as dichloromethane or tetrahydrofuran) followed by subsequent lactamisation conditions in a suitable solvent (such as toluene) with a suitable Lewis acid (such as trimethylaluminium).

Compounds of formula (IX) are either commercially available or well known in the art.

A compound of formula (IV), wherein R² is an alkyl group (such as methyl or ethyl), may be prepared from a compound of formula (V), by reaction with a compound of formula (X), wherein P² is a suitable protecting group (such as-Boc), in the presence of a suitable base (such as sodium hydride or K2CO3) in a suitable solvent (such as N,N- dimethylformamide or dioxane) under conditions of ambient or elevated temperatures

(such as achieved by heating or by microwave irradiation). The protecting group P² can be removed from compounds of formula (X) by the use of a suitable acid (such as

trifluoroacetic acid or HC1) in a suitable solvent (such as dioxane or DCM).

Compounds of formula (X) are either commercially available or well known in the art.

The reaction of compound of formula (V) with a compound of formula (X) to prepare a compound of formula (IV) is novel and provides a further aspect of this invention.

Therefore in a further aspect, there is provided a process for preparing a compound of formula (IV), said process comprising:

a) reaction of a compound of formula (V) with a compound of formula (X) in the presence of a suitable base in a suitable solvent, under conditions of ambient or elevated temperatures;

wherein;

R² is an alkyl group;

L¹ is a leaving group;

P² is a protecting group; and

b) removal of the protecting group P² in the presence of a suitable acid in a suitable solvent.

In one embodiment,

In one embodiment, L² is

In one embodiment,

formula (X) is performed in N,N-dimethylformamide or dioxane.

In one embodiment, reaction of a compound of formula (V) with a compound of formula (X) is performed in dioxane.

In one embodiment, reaction of a compound of formula (V) with a compound of formula (X) is performed in N,N-dimethylformamide. In one embodiment, reaction of a compound of formula (V) with a compound of formula (X) is performed at temperatures at about 20°C.

In one embodiment, reaction of a compound of formula (V) with a compound of formula (X) is performed at temperatures of 18-25°C.

In one embodiment, reaction of a compound of formula (V) with a compound of formula (X) is performed at temperatures > 20°C.

In one embodiment, reaction of a compound of formula (V) with a compound of formula (X) is performed at temperatures >50°C.

In one embodiment, reaction of a compound of formula (V) with a compound of formula (X) is performed at temperatures >80°C.

In one embodiment, reaction of a compound of formula (V) with a compound of formula (X) is performed at temperatures >90°C.

In one embodiment, reaction of a compound of formula (V) with a compound of formula (X) is performed at temperatures 90-110°C.

In one embodiment, reaction of a compound of formula (V) with a compound of formula (X) is performed at temperatures 95-105°C.

In one embodiment, reaction of a compound of formula (V) with a compound of formula (X) is performed at temperatures <110°C.

In one embodiment, a suitable acid is HC1 or trifluoroacetic acid.

In one embodiment, a suitable acid is HC1.

In one embodiment, a suitable acid is trifluoroacetic acid.

In one embodiment, P² is -Boc.

In one embodiment, removal of the protecting group P² is performed in dioxane or

In one embodiment, removal of the protecting group P² is performed in dioxane. In one embodiment, removal of the protecting group P² is performed in DCM. In one embodiment, removal of the protecting group P² is at temperatures of 18-

In one embodiment, removal of the protecting group P² is at temperatures of 22-

In one embodiment, removal of the protecting group P² is at temperatures at about In one embodiment, removal of the protecting group P² is at temperatures at about

25°C.

(vi) (V)

A compound of formula (V) wherein L¹ is a suitable leaving group (such as halogen, or -S0₂Me, etc) may be prepared from a compound of formula (VI), wherein R² is an alkyl group (such as methyl or ethyl), R³ is either H or a suitable alkyl group (such as iPr or R₃'s are joined to make a ring such as 4,4,5 ,5-tetramethyl-l,3,2-dioxaborolane) and P³ is a protecting group (such as -Boc) by reaction with a compound of formula (XI) wherein L³ is a suitable leaving group (such as halo, or OS0₂CF₃), in the presence of a suitable Pd catalyst and phosphine ligand, with a suitable base (such as sodium carbonate or caesium carbonate) in a suitable solvent (such as a mixture of dioxane and water), under suitable conditions (such as heating thermally or in a microwave reactor). The protecting group P³ can then be readily removed with an acid (such as trifluoro acetic acid) in a suitable solvent (such as dichloromethane or dioxane).

Compound of formula VI and XI can be prepared by methods well known in the art.

When a pharmaceutically-acceptable salt of a compound of the Formula (I) is required it may be obtained by, for example, reaction of said compound with a suitable acid or suitable base.

When a pharmaceutically-acceptable pro-drug of a compound of the Formula (I) is required, it may be obtained using a conventional procedure. For example, an in-vivo cleavable ester of compound of the Formula (I) may be obtained by, for example, reaction of a compound of the Formula (I) containing a carboxy group with a pharmaceutically- acceptable alcohol. Further information on pro-drugs has been provided hereinbefore.

It will also be appreciated that, in some of the reactions mentioned hereinbefore, it may be necessary or desirable to protect any sensitive groups in the compounds. The instances where protection is necessary or desirable, and suitable methods for protection, are known to those skilled in the art. Conventional protecting groups may be used in accordance with standard practice (for illustration see T.W. Green, Protective Groups in Organic Synthesis, John Wiley and Sons, 1991). Thus, if reactants include groups such as amino, carboxy or hydroxy, it may be desirable to protect the group in some of the reactions mentioned herein.

A suitable protecting group for an amino or alkylamino group is, for example, an acyl group, for example an alkanoyl group such as acetyl, an alkoxycarbonyl group, for example a methoxycarbonyl, ethoxycarbonyl or t-butoxycarbonyl group, an

arylmethoxycarbonyl group, for example benzyloxycarbonyl, or an aroyl group, for example benzoyl. The deprotection conditions for the above protecting groups necessarily vary with the choice of protecting group. Thus, for example, an acyl group such as an alkanoyl or alkoxycarbonyl group or an aroyl group may be removed for example, by hydrolysis with a suitable base such as an alkali metal hydroxide, for example lithium or sodium hydroxide. Alternatively an acyl group such as a t-butoxycarbonyl group may be removed, for example, by treatment with a suitable acid as hydrochloric, sulphuric or phosphoric acid or trifluoroacetic acid and an arylmethoxycarbonyl group such as a benzyloxycarbonyl group may be removed, for example, by hydrogenation over a catalyst such as palladium-on-carbon, or by treatment with a Lewis acid for example boron tris(trifluoroacetate). A suitable alternative protecting group for a primary amino group is, for example, a phthaloyl group which may be removed by treatment with an alkylamine, for example dimethylaminopropylamine, or with hydrazine.

A suitable protecting group for a hydroxy group is, for example, an acyl group, for example an alkanoyl group such as acetyl, an aroyl group, for example benzoyl, or an arylmethyl group, for example benzyl. The deprotection conditions for the above protecting groups will necessarily vary with the choice of protecting group. Thus, for example, an acyl group such as an alkanoyl or an aroyl group may be removed, for example, by hydrolysis with a suitable base such as an alkali metal hydroxide, for example lithium or sodium hydroxide. Alternatively an arylmethyl group such as a benzyl group may be removed, for example, by hydrogenation over a catalyst such as

palladium-on-carbon.

A suitable protecting group for a carboxy group is, for example, an esterifying group, for example a methyl or an ethyl group which may be removed, for example, by hydrolysis with a base such as sodium hydroxide, or for example a t-butyl group which may be removed, for example, by treatment with an acid, for example an organic acid such as trifluoroacetic acid, or for example a benzyl group which may be removed, for example, by hydrogenation over a catalyst such as palladium-on-carbon.

The protecting groups may be removed at any convenient stage in the synthesis using conventional techniques well known in the chemical art.

Certain of the intermediates (for example, compounds of the Formulae II, III, IV, and V particularly Formulae III and IV) defined herein are novel and these are provided as a further features of the invention.

Biological Assavs-

The following assays were used to measure the effects of the compounds of the present invention.

Compound Handling

All compounds or DMSO (dimethyl sulphoxide) for the ERK2 Mass Spectrometry and A375 phospho-p90RSK assays were dispensed from source plates containing compounds at lOmM in 100% (v/v) DMSO or 100% DMSO, directly into assay plates using an Echo 555 Acoustic dispenser (Labcyte Inc™). Depending on the assay, two separate plate preparation workflows were followed. In Workflow A, lOmM compound stocks were diluted 1 : 100 using a fixed-tip 96-head Agilent VPrep liquid handler (Agilent Technologies, Santa Clara, CA) to give four intermediate dilutions (lOmM, ΙΟΟμΜ, ΙμΜ, ΙΟηΜ). In Workflow B, lOmM compound stocks were diluted 1 :10 using a Tecan Freedom Evo (Tecan Group Ltd., Switzerland), and then 1 : 100 using the Echo 555 and Labcyte LX to produce three intermediate dilutions across three Labcyte qualified source plates (ImM, 10μΜ, ΙΟΟηΜ). These intermediate dilution plates were then used by the Echo 555 to generate final assay-ready compound plates with a 12 point dose range (10, 3, 1, 0.25, 0.1, 0.03, 0.01, 0.0025, 0.001, 0.0003, 0.0001, 0.0000125μΜ) in order to calculate compound IC50S, with a total DMSO concentration in the assay of 1%. For the ERK2 Mass spectrometry assay Workflow B was used. For the A375 phospho-p90RSK cell assay, the intermediate 1 :100 dilution plate described in Workflow A was used by the Echo to dispense compounds and DMSO directly into the cell plates with a 12 point dose range (30, 10, 3.125, 1.25, 0.3, 0.1, 0.03125, 0.0125, 0.003, 0.001, 0.0003125, 0.00003μΜ) in order to calculate compound ICsos, with a total DMSO concentration in the assay of 0.3%.

ERK2 Rapidfire Mass Spectrometry Inhibition of Catalysis Assay

MEK U911 -activated ER 2 protein was expressed and purified in-house. Enzyme and substrate solutions were made up in assay buffer consisting of 50mM Tris (pH 7.5), lOmM MgC12, O.lmM EGTA (ethylene glycol tetraacetic acid), lOmM DTT

(dithiothreitol) and 0.01% (v/v) CHAPS (3-[(3-Cholamidopropyl)dimethylammonio]-l- propanesulfonate). 1.2nM ERK2 protein was prepared in assay buffer and ΙΟμΙ was dispensed into each well of a polypropylene, 384-well plate (#781201, Greiner) containing test and reference control compounds. Following a 15 minute pre-incubation of enzyme and compound at room temperature, ΙΟμΙ of substrate solution was added consisting of 16μΜ Erktide (IPTTPITTTYFFFK, #61777, AnaSpec) and 120μΜ ATP (adenosine triphosphate) (measured Km) in assay buffer. The reaction was allowed to progress for 20 minutes at room temperature before being quenched by the addition of 80μ1 1% (v/v) formic acid. The assay plates were then run on the RapidFire Mass Spectrometry platform (Agilent) to measure substrate (unphosphorylated Erktide) and product (phosphorylated Erktide) levels. Data was analysed and IC50's (half maximal inhibitory concentration) were calculated using Genedata Screener® software.

A375 phospho-p90RSK Cellular Assay

The phospho-p90RSK cell assay was performed in the A375 cell line, a human malignant melanoma which has a BRAF mutation up-regulating the MAPK pathway and, hence, elevated endogenous levels of phospho-ERK and phospho-p90RSK. A375 cells were cultured in cell media composed of DMEM (Dulbecco's modified Eagle's medium), 10%) (v/v) Foetal Calf Serum and 1% (v/v) L-Glutamine. After harvesting, cells were dispensed into black, 384-well Costar plates (#3712, Corning) to give 2400 cells per well in a total volume of 40μ1 cell media, and were incubated overnight at 37°C, 90% relative humidity and 5% C0₂ in a rotating incubator. Test compounds and reference controls were dosed directly into the cell plates using a Labcyte Echo 555 acoustic dispenser. The cell plates were then incubated for 2 hours at 37°C before being fixed by the addition of 20μ1 12% formaldehyde in PBS/A (4% final concentration), followed by a 20 minute room temperature incubation, and then a 2x wash with 150μ1 PBS/A (phosphate buffered saline containing albumin) using a BioTek ELx405 platewasher. Cells were permeabilised with 20μ1 0.1% Triton X-100 in PBS/A for 20 minutes at room temperature, and then washed lx with ΙΟΟμΙ PBS/A. Primary phospho-p90RSK (Thr359) (D1E9) rabbit monoclonal antibody (#8753, Cell Signaling Technology) was diluted 1 : 1000 in assay buffer (0.05% (v/v) Tween, 5% (v/v) Foetal Calf Serum, in PBS/A), 20μ1 added per well, and plates were incubated at 4°C overnight. Cell plates were washed 2x with 200μ1 PBS/T (phosphate buffered saline containing Tween-20), then 20μ1 1 :500 dilution in assay buffer of Alexa Fluor® 647 goat anti-rabbit IgG secondary antibody (#A31573, Molecular Probes, Life Technologies), with a 1 :5000 dilution of Hoechst 33342, was added per well. Following a 90 minute incubation at room temperature, plates were washed 2x with 200μ1 PBS/T, and 40μ1 PBS/A was added per well. Stained cell plates were covered with black lid seals, and then read on a Cellomics ArrayScanTM VTI imaging platform (Thermo Scientific), using an XF53 filter with lOx objective, with a LED light source set-up to analyse nuclear staining with Hoechst 33342 (405nm) and secondary antibody staining of phospho- p90RSK (647nm). Data was analysed and IC50's were calculated using Genedata Screener® software.

Compounds as claimed herein generally have enzyme activity in the above assay of <0.5 mM, such as <0.2 mM.

The following data were generated for the Examples (the data below may be a result from a single experiment or an average of two or more experiments; variations from data presented in applications from which this application claims priority are due to further repetitions of the test causing slight changes in average values):

Example ERK2 Mass p90RSK cell ICso

Spectrometry (μΜ)

Enzyme ICso (μΜ)

1 0.0005 0.088

2 0.0004 0.071

3 0.0007 0.36

4 0.0005 0.092

5 0.0006 0.84 0.0032 2.5

Compounds of the examples have been shown to be at least 1000 fold more selective for ERK2 over MEK in the MEK Autophosphorylation ADP-Glo Assay below. MEK Autophosphorylation ADP-Glo Assay

Activated MEK protein was supplied by MRC-PPU (DU911, Dundee, UK) or expressed and purified in-house. The MEK assay was performed with the ADP-Glo™ Kinase Assay Kit (Promega, Madison, WI, USA), in Greiner 384-well white low volume plates. 2 μΐ of 6 nM activated MEK protein, in assay buffer consisting of 50 mM Tris (pH 7.5), 10 mM DTT, 0.1 mM EGTA, 0.01% v/v Tween20 and 10 mM MgCl₂, was dispensed into each well of a plate containing test and reference control compounds. Following a 15 minute pre-incubation of enzyme and compound at room temperature, 2 μΐ of substrate solution was added consisting of 20 μΜ ATP ( TMap_P ^ATP) in assay buffer. The assay reaction was allowed to proceed for 90 min at room temperature before stopping the reaction by the addition of 2 μΐ of ADP-Glo reagent. Plates were then covered and incubated for 40 min at room temperature. 4 μΐ Kinase Detection Reagent was then added and plates were incubated for 30 min, before the luminescence signal was read with a PHERAstar plate reader (BMG Labtech GmbH, Offenburg, Germany).

According to a further aspect of the disclosure there is provided a pharmaceutical composition, which comprises a compound of the Formula (I), or a

pharmaceutically-acceptable salt thereof, as defined hereinbefore in association with a pharmaceutically-acceptable diluent or carrier.

Suitable pharmaceutically-acceptable excipients for a tablet formulation include, for example, inert diluents, granulating and disintegrating agents, binding agents, lubricating agents, preservative agents and antioxidants. A further suitable

pharmaceutically-acceptable excipient may be a chelating agent. Tablet formulations may be uncoated or coated either to modify their disintegration and the subsequent absorption of the active ingredient within the gastrointestinal tract, or to improve their stability and/or appearance, in either case, using conventional coating agents and procedures well known in the art. Compositions for oral use may alternatively be in the form of hard gelatin capsules in which the active ingredient is mixed with an inert solid diluent, or as soft gelatin capsules in which the active ingredient is mixed with water or an oil.

Aqueous suspensions generally contain the active ingredient in finely powdered form together with one or more suspending agents, dispersing or wetting agents. The aqueous suspensions may also contain one or more preservatives, anti-oxidants, colouring agents, flavouring agents, and/or sweetening agents.

Oily suspensions may be formulated by suspending the active ingredient in a vegetable oil or in a mineral oil. The oily suspensions may also contain a thickening agent. Sweetening agents such as those set out above, and flavouring agents may be added to provide a palatable oral preparation. These compositions may be preserved by the addition of an anti-oxidant.

Dispersible powders and granules suitable for preparation of an aqueous suspension by the addition of water generally contain the active ingredient together with a dispersing or wetting agent, suspending agent and one or more preservatives. Additional excipients such as sweetening, flavouring and colouring agents, may also be present.

The pharmaceutical compositions of the invention may also be in the form of oil-in-water emulsions. The oily phase may be a vegetable oil or a mineral oil or a mixture of any of these. The emulsions may also contain sweetening, flavouring and preservative agents.

Syrups and elixirs may be formulated with sweetening agents, and may also contain a demulcent, preservative, flavouring and/or colouring agent.

The pharmaceutical compositions may also be in the form of a sterile injectable aqueous or oily suspension, which may be formulated according to known procedures using one or more of the appropriate dispersing or wetting agents and suspending agents, which have been mentioned above. A sterile injectable preparation may also be a sterile injectable solution or suspension in a non-toxic parenterally-acceptable diluent or solvent system.

Compositions for administration by inhalation may be in the form of a conventional pressurised aerosol arranged to dispense the active ingredient either as an aerosol containing finely divided solid or liquid droplets. Conventional aerosol propellants such as volatile fluorinated hydrocarbons or hydrocarbons may be used and the aerosol device is conveniently arranged to dispense a metered quantity of active ingredient. Dry powder inhalers may also be suitable.

For further information on formulation the reader is referred to Chapter 25.2 in Volume 5 of Comprehensive Medicinal Chemistry (Corwin Hansch; Chairman of Editorial Board), Pergamon Press 1990.

The amount of active ingredient that is combined with one or more excipients to produce a single dosage form will necessarily vary depending upon the host treated and the particular route of administration. For example, oral administration to humans will generally require, for example, from 1 mg to 2 g of active agent (more suitably from lOOmg to 2g, for example from 250 mg to 1.8g, such as from 500mg to 1.8g, particularly from 500mg to 1.5g, conveniently from 500mg to lg) to be administered compounded with an appropriate and convenient amount of excipients which may vary from about 3 to about 98 percent by weight of the total composition. It will be understood that, if a large dosage is required, multiple dosage forms may be required, for example two or more tablets or capsules, with the dose of active ingredient divided conveniently between them. Typically, unit dosage forms will contain about 10 mg to 0.5 g of a compound of this invention, although a unit dosage form may contain up to lg. Conveniently, a single solid dosage form may contain between 1 and 300mg of active ingredient.

The size of the dose for therapeutic or prophylactic purposes of compounds of the present invention will naturally vary according to the nature and severity of the disease state, the age and sex of the animal or patient and the route of administration, according to well known principles of medicine.

In using compounds of the present invention for therapeutic or prophylactic purposes it will generally be administered so that a daily dose in the range, for example, 1 mg/kg to 100 mg/kg body weight is received, given if required in divided doses. In general, lower doses will be administered when a parenteral route is employed. Thus, for example, for intravenous administration, a dose in the range, for example, 1 mg/kg to 25 mg/kg body weight will generally be used. Similarly, for administration by inhalation, a dose in the range, for example, 1 mg/kg to 25 mg/kg body weight will be used. Oral administration is however preferred, particularly in tablet form.

In one aspect of the invention, compounds of the present invention or

pharmaceutically-acceptable salts thereof, are administered as tablets comprising lOmg to 500mg of the compound of Formula (I) (or a pharmaceutically-acceptable salt thereof), wherein one or more tablets are administered as required to achieve the desired dose.

As stated above, it is known that signalling through ERK causes tumourigenesis by one or more of the effects of mediating proliferation of cancer and other cells, mediating angiogenic events and mediating the motility, migration and invasiveness of cancer cells. We have found that the compounds of the present invention possess potent anti -tumour activity which it is believed is obtained by way of inhibition of ERK that is involved in the signal transduction steps which lead to the proliferation and survival of tumour cells and the invasiveness and migratory ability of metastasising tumour cells.

Accordingly, the compounds of the present invention may be of value as anti-tumour agents, in particular as selective inhibitors of the proliferation, survival, motility,

dissemination and invasiveness of mammalian cancer cells leading to inhibition of tumour growth and survival and to inhibition of metastatic tumour growth. Particularly, the compounds of the present invention may be of value as anti-proliferative and anti -invasive agents in the containment and/or treatment of solid tumour disease. Particularly, the compounds of the present invention may be useful in the prevention or treatment of those tumours which are sensitive to inhibition of ERK and that are involved in the signal transduction steps which lead to the proliferation and survival of tumour cells and the migratory ability and invasiveness of metastasising tumour cells. Further, the compounds of the present invention may be useful in the prevention or treatment of those tumours which are mediated alone or in part by inhibition of ERK, i.e. the compounds may be used to produce an ERK inhibitory effect in a warm-blooded animal in need of such treatment.

According to a further aspect there is provided a compound of the Formula (I), or a pharmaceutically-acceptable salt thereof, as defined hereinbefore for use as a medicament in a warm-blooded animal such as man.

According to a further aspect, there is provided a compound of the Formula (I), or a pharmaceutically-acceptable salt thereof, as defined hereinbefore for use in the production of an anti-proliferative effect in a warm-blooded animal such as man.

According to a further aspect there is provided a compound of the Formula (I), or a pharmaceutically-acceptable salt thereof, as defined hereinbefore for use in a warm-blooded animal such as man as an anti-invasive agent in the containment and/or treatment of solid tumour disease. According to a further aspect there is provided the use of a compound of the Formula (I), or a pharmaceutically-acceptable salt thereof, as defined hereinbefore, for the production of an anti-proliferative effect in a warm-blooded animal such as man.

According to a further aspect there is provided the use of a compound of the Formula (I), or a pharmaceutically-acceptable salt thereof, as defined hereinbefore, in the

manufacture of a medicament for use in the production of an anti-proliferative effect in a warm-blooded animal such as man.

manufacture of a medicament for use in a warm-blooded animal such as man as an anti- invasive agent in the containment and/or treatment of solid tumour disease.

According to a further aspect there is provided a method for producing an antiproliferative effect in a warm-blooded animal, such as man, in need of such treatment which comprises administering to said animal an effective amount of a compound of the Formula (I), or a pharmaceutically-acceptable salt thereof, as defined hereinbefore.

According to a further aspect there is provided a method for producing an anti- invasive effect by the containment and/or treatment of solid tumour disease in a warmblooded animal, such as man, in need of such treatment which comprises administering to said animal an effective amount of a compound of the Formula (I), or a pharmaceutically- acceptable salt thereof, as defined hereinbefore.

According to a further aspect, there is provided a compound of the Formula (I), or a pharmaceutically-acceptable salt thereof, as defined hereinbefore, for use in the prevention or treatment of cancer in a warm-blooded animal such as man.

According to a further aspect there is provided the use of a compound of the Formula (I), or a pharmaceutically-acceptable salt thereof, as defined hereinbefore in the manufacture of a medicament for use in the prevention or treatment of cancer in a warm-blooded animal such as man.

According to a further aspect there is provided a method for the prevention or treatment of cancer in a warm-blooded animal, such as man, in need of such treatment which comprises administering to said animal an effective amount of a compound of the Formula (I), or a pharmaceutically-acceptable salt thereof, as defined hereinbefore. According to a further aspect, there is provided a compound of the Formula (I), or a pharmaceutically-acceptable salt thereof, as defined hereinbefore for use in the prevention or treatment of solid tumour disease in a warm-blooded animal such as man.

manufacture of a medicament for use in the prevention or treatment of solid tumour disease in a warm-blooded animal such as man.

According to a further aspect there is provided a method for the prevention or treatment of solid tumour disease in a warm-blooded animal, such as man, in need of such treatment which comprises administering to said animal an effective amount of a compound of the Formula (I), or a pharmaceutically-acceptable salt thereof, as defined hereinbefore.

According to a further aspect, there is provided a method for reducing the number of cancer cell in an individual in need of such treatment which comprises administering to said animal an effective amount of a compound of the Formula (I), or a pharmaceutically- acceptable salt thereof, as defined hereinbefore.

According to a further aspect, there is provided a method for reducing the size of a tumour in need of such treatment which comprises administering to said animal an effective amount of a compound of the Formula (I), or a pharmaceutically-acceptable salt thereof, as defined hereinbefore.

According to a further aspect, there is provided a method for reducing or inhibiting growth or proliferation of a tumour in need of such treatment which comprises administering to said animal an effective amount of a compound of the Formula (I), or a pharmaceutically- acceptable salt thereof, as defined hereinbefore.

According to a further aspect, there is provided a method for preventing metastasis or reducing the extent of metastasis in need of such treatment which comprises

administering to said animal an effective amount of a compound of the Formula (I), or a pharmaceutically-acceptable salt thereof, as defined hereinbefore.

According to a further aspect, there is provided a method for extending the survival (including but not limited to progression free survival (PFS) or overall survival) in an individual having or at risk of having cancer in need of such treatment which comprises administering to said animal an effective amount of a compound of the Formula (I), or a pharmaceutically-acceptable salt thereof, as defined hereinbefore. The phrase "effective amount" or "therapeutically-effective amount" means an amount that (i) treats the particular disease, condition or disorder, (ii) attenuates, ameliorates or eliminates one or more symptoms of the particular disease, condition or disorder, (iii) delays or prevents the onset of one or more symptoms of the particular disease, condition or disorder described herein. In the case of cancer, the effective amount may reduce the number of cancer cells; reduce the tumour size; inhibit (eg slow to some extent and preferably stop) infiltration of the cancer cells into peripheral organs; inhibit tumour metastasis; inhibit to some extent tumour growth; and/or relieve to some extent one or more of the symptoms associated with cancer. For cancer therapy, efficacy can be measure by assessing, for example the time to disease progression (TTP) and/or assessing the response rate (RR).

According to a further aspect there is provided a compound of the Formula (I), or a pharmaceutically-acceptable salt thereof, as defined hereinbefore, for use in the prevention or treatment of a hyperproliferative disease or disorder modulated by RAS/RAF/MEK/ERK kinases.

manufacture of a medicament for use in the prevention or treatment of a hyperproliferative disease or disorder modulated by RAS/RAF/MEK/ERK kinases.

According to a further aspect there is provided a method for the prevention or treatment of a hyperproliferative disease or disorder modulated by RAS/RAF/MEK/ERK kinases which comprises administering to said animal an effective amount of a compound of the Formula (I), or a pharmaceutically-acceptable salt thereof, as defined hereinbefore.

According to a further aspect there is provided a compound of the Formula (I), or a pharmaceutically-acceptable salt thereof, as defined hereinbefore, for use in the prevention or treatment of a hyperproliferative disease or disorder mediated by ERK.

manufacture of a medicament for use in the prevention or treatment of a hyperproliferative disease or disorder mediated by ERK.

According to a further aspect there is provided a method for the prevention or treatment of a hyperproliferative disease or disorder mediated by ERK which comprises administering to said animal an effective amount of a compound of the Formula (I), or a pharmaceutically-acceptable salt thereof, as defined hereinbefore.

According to a further aspect there is provided a compound of the Formula (I), or a pharmaceutically-acceptable salt thereof, as defined hereinbefore, for use in the prevention or treatment of those tumours which are sensitive to inhibition of ERK.

manufacture of a medicament for use in the prevention or treatment of those tumours which are sensitive to inhibition of ERK.

According to a further aspect there is provided a method for the prevention or treatment of those tumours which are sensitive to inhibition of ERK which comprises administering to said animal an effective amount of a compound of the Formula (I), or a pharmaceutically-acceptable salt thereof, as defined hereinbefore.

According to a further aspect there is provided a compound of the Formula (I), or a pharmaceutically-acceptable salt thereof, as defined hereinbefore for use in providing an inhibitory effect on ERK.

According to a further aspect there is provided the use of a compound of the Formula (I), or a pharmaceutically-acceptable salt thereof, as defined hereinbefore in the manufacture of a medicament for use in providing an inhibitory effect on ERK.

According to a further aspect there is also provided a method for providing an inhibitory effect on ERK which comprises administering an effective amount of a compound of the Formula (I), or a pharmaceutically-acceptable salt thereof, as defined hereinbefore.

According to a further aspect there is provided a compound of the Formula (I), or a pharmaceutically-acceptable salt thereof, as defined hereinbefore, for use in providing a selective inhibitory effect on ERK2.

manufacture of a medicament for use in providing a selective inhibitory effect on ERK2.

According to a further aspect there is also provided a method for providing a selective inhibitory effect on ERK2 which comprises administering an effective amount of a compound of the Formula (I), or a pharmaceutically-acceptable salt thereof, as defined hereinbefore. Compounds of Formula (I) may be effective in treating any cancer where the RAS/RAF/MEK/ERK kinase pathway is activated. Examples of cancers which have been reported to have such activation include acute myelogenous leukemia (AML), chronic myelomonocyic leukemia, multiple myeloma, chronic myelogenous leukemia, colorectal cancer (CRC), breast cancer, bladder cancer, head and neck cancer, brain cancer, glioblastoma, neuroblastoma, Non-Hodgkins lymphoma, pancreatic cancer, ovarian cancer, testicular cancer, thyroid cancer, non-small cell lung cancer (NSCLC), small cell lung cancer, melanoma, neurofibromatosis type 1 (NF1), biliary tract.

In one aspect, compounds may be effective in treating a cancer selected from NSCLC, pancreatic, CRC, melanoma, uveal melanoma, paediatric NF1, differentiated thyroid and biliary tract cancer.

In one aspect, compounds may be effective in treating KRAS or BRAF mutant cancers.

In one aspect, compounds may be effective in treating MAPK pathway dependent cancers such as NSCLC, pancreatic and CRC; in some embodiments such cancers are KRAS mutant cancers as described hereinafter.

In another aspect, compounds may be effective in treating BRAF mutant melanoma.

In a further aspect, compounds may be effective in treating a cancer selected from NRAS mutant melanoma, uveal melanoma, paediatric NF1, differentiated thyroid and biliary tract cancer.

According to a further aspect there is provided a compound of the Formula (I), or a pharmaceutically-acceptable salt thereof, as defined hereinbefore, for use in the treatment of NSCLC, pancreatic, CRC, melanoma, uveal melanoma, paediatric NF1, differentiated thyroid and biliary tract cancers.

According to a further aspect there is provided a compound of the Formula (I), or a pharmaceutically-acceptable salt thereof, as defined hereinbefore, for use in the treatment of NSCLC, pancreatic and CRC.

According to a further aspect there is provided a compound of the Formula (I), or a pharmaceutically-acceptable salt thereof, as defined hereinbefore, for use in the treatment of BRAF mutant melanoma.

According to a further aspect there is provided a compound of the Formula (I), or a pharmaceutically-acceptable salt thereof, as defined hereinbefore, for use in the treatment of NRAS mutant melanoma, uveal melanoma, paediatric NF1, differentiated thyroid and biliary tract cancer.

According to a further aspect there is provided a compound of the Formula (I), or a pharmaceutically-acceptable salt thereof, as defined hereinbefore, for use in the treatment of a cancer mediated by ERK, wherein the cancer has developed resistance to one or more other MAPK pathway inhibitors.

According to a further aspect there is provided a method for treating a cancer selected from NSCLC, pancreatic, CRC, melanoma, uveal melanoma, paediatric NF1, differentiated thyroid and biliary tract cancers, which comprises administering an effective amount of a compound of the Formula (I), or a pharmaceutically-acceptable salt thereof, as defined hereinbefore.

According to a further aspect there is provided a method for treating a cancer selected from NSCLC, pancreatic and CRC, which comprises administering an effective amount of a compound of the Formula (I), or a pharmaceutically-acceptable salt thereof, as defined hereinbefore.

According to a further aspect there is provided a method for treating BRAF mutant melanoma, which comprises administering an effective amount of a compound of the Formula (I), or a pharmaceutically-acceptable salt thereof, as defined hereinbefore.

According to a further aspect there is provided a method for treating a cancer selected from NRAS mutant melanoma, uveal melanoma, paediatric NF1, differentiated thyroid and biliary tract cancer, which comprises administering an effective amount of a compound of the Formula (I), or a pharmaceutically-acceptable salt thereof, as defined hereinbefore.

According to a further aspect there is provided a method for treating a cancer mediated by ERK, wherein the cancer has developed resistance to one or more other MAPK pathway inhibitors, which comprises administering an effective amount of a compound of the Formula (I), or a pharmaceutically-acceptable salt thereof, as defined hereinbefore.

manufacture of a medicament for use in the treatment of a cancer selected from NSCLC, pancreatic, CRC, melanoma, uveal melanoma, paediatric NF1, differentiated thyroid and biliary tract cancers. According to a further aspect there is provided the use of a compound of the Formula (I), or a pharmaceutically-acceptable salt thereof, as defined hereinbefore, in the

manufacture of a medicament for use in the treatment of a cancer selected from NSCLC, pancreatic and CRC.

manufacture of a medicament for use in the treatment of BRAF mutant melanoma.

manufacture of a medicament for use in the treatment of NRAS mutant melanoma, uveal melanoma, paediatric NF1, differentiated thyroid and biliary tract cancer.

manufacture of a medicament for use in the treatment of a cancer mediated by ERK, wherein the cancer has developed resistance to one or more other MAPK pathway inhibitors.

As stated hereinbefore, the in-vivo effects of a compound of the Formula (I) may be exerted in part by one or more metabolites that are formed within the human or animal body after administration of a compound of the Formula (I).

In the above compositions, methods and uses, particular compounds of Formula (I) are the compounds of the Examples, or pharmaceutically-acceptable salts thereof. Further illustrative examples for compositions, methods and uses are:

(5)-3-Methyl-7-(5-methyl-2-((l-methyl-lH-pyrazol-5-yl)amino)pyridin-4-yl)-2-((2- methyl-2H-l,2,3-triazol-4-yl)methyl)-3,4-dihydropyrrolo[l,2-a]pyrazin-l(2H)-one;

(5)-3-methyl-2-((l-methyl-lH-l,2,3-triazol-5-yl)methyl)-7-(5-methyl-2-((l-methyl-lH- pyrazol-5-yl)amino)pyridin-4-yl)-3,4-dihydropyrrolo[l,2-a]pyrazin-l(2H)-one; and (5)-3-methyl-2 (l-methyl H ,2,3-triazol-4-yl)methyl)-7-(5-methyl-2-((l-methyl-lH- pyrazol-5-yl)amino)pyridin-4-yl)-3,4-dihydropyrrolo[l,2-a]pyrazin-l(2H)-one.

The anti-cancer treatment defined herein may be applied as a sole therapy or may involve, in addition to the compounds of the invention, conventional surgery or

radiotherapy or chemotherapy. In certain embodiments, a compound of formula (I) is combined with another compound which has anti-hyperproliferative properties or that is useful in treating a hyperproliferative disorder. The additional compound may suitably have complementary activities to the compound of formula (I) such that they do not adversely affect each other. In some aspects such combination therapy may prevent or delay inherent or acquired resistance attributable to activation of the RAS/RAF/MEK/ERK pathway observed with MEK inhibition and to prevent or delay inherent or acquired resistance mediated via RAS pathway activation.

In addition to providing improved treatment for a given hyperproliferative disorder, administration of certain combinations may improve the quality of life of a patient compared to the quality of life experienced by the same patient receiving a different treatment. For example, administration of a combination to a patient may provide an improved quality of life compared to the quality of life the same patient would experience if they received only one of the individual agents as therapy. For example, a combined therapy may lower the dose of the therapeutic agents required. The combination may also cause reduced tumour burden and thereby reduce the associated adverse events.

Accordingly, in one embodiment there is provided a compound of Formula (I), or a pharmaceutically-acceptable salt thereof, and an additional anti-tumour substance for the conjoint treatment of cancer.

The anti-cancer treatment defined hereinbefore may be applied as a sole therapy or may involve, in addition to the compound of the invention, conventional surgery or radiotherapy or chemotherapy. Such chemotherapy may include one or more of the following categories of anti-tumour agents :-

(i) antiproliferative/antineoplastic drugs and combinations thereof, as used in medical oncology, such as alkylating agents (for example cis-platin, oxaliplatin, carboplatin, cyclophosphamide, nitrogen mustard, melphalan, chlorambucil, busulphan, temozolamide and nitrosoureas); antimetabolites (for example gemcitabine and antifolates such as fluoropyrimidines like 5-fluorouracil and tegafur, raltitrexed, methotrexate, cytosine arabinoside, and hydroxyurea); antitumour antibiotics (for example anthracyclines like adriamycin, bleomycin, doxorubicin, daunomycin, epirubicin, idarubicin, mitomycin-C, dactinomycin and mithramycin); antimitotic agents (for example vinca alkaloids like vincristine, vinblastine, vindesine and vinorelbine and taxoids like taxol and taxotere and polokinase inhibitors); and topoisomerase inhibitors (for example epipodophyllotoxins like etoposide and teniposide, amsacrine, topotecan and camptothecin);

(ii) antihormonal agents such as antioestrogens (for example tamoxifen, fulvestrant, toremifene, raloxifene, droloxifene and iodoxyfene), antiandrogens (for example bicalutamide, flutamide, nilutamide and cyproterone acetate), LHRH antagonists or LHRH agonists (for example goserelin, leuprorelin and buserelin), progestogens (for example megestrol acetate), aromatase inhibitors (for example as anastrozole, letrozole, vorazole and exemestane) and inhibitors of 5a-reductase such as finasteride;

(iii) inhibitors of growth factor function and their downstream signalling pathways: included are Ab modulators of any growth factor or growth factor receptor targets, reviewed by Stern et al. Critical Reviews in Oncology/Haematology, 2005, 54, ppl 1-29); also included are small molecule inhibitors of such targets, for example kinase inhibitors - examples include the anti-erbB2 antibody trastuzumab [Herceptin™], the anti-EGFR antibody panitumumab, the anti-EGFR antibody cetuximab [Erbitux, C225] and tyrosine kinase inhibitors including inhibitors of the erbB receptor family, such as epidermal growth factor family receptor (EGFR/erbBl) tyrosine kinase inhibitors such as gefitinib or erlotinib, erbB2 tyrosine kinase inhibitors such as lapatinib, and mixed erbl/2 inhibitors such as afatanib; similar strategies are available for other classes of growth factors and their receptors, for example inhibitors of the hepatocyte growth factor family or their receptors including c-met and ron; inhibitors of the insulin and insulin growth factor family or their receptors (IGFR, IR) inhibitors of the platelet-derived growth factor family or their receptors (PDGFR), and inhibitors of signalling mediated by other receptor tyrosine kinases such as c-kit, AnLK, and CSF-1R;

also included are modulators which target signalling proteins in the wider PI3 -kinase signalling pathway, for example, inhibitors of other PI3-kinase isoforms such as PI3K- β, and ser / thr kinases such as AKT, mTOR, PDK, SGK, PI4K or PIP5K;

also included are inhibitors of serine/threonine kinases not listed above, for example raf inhibitors such as vemurafenib, MEK inhibitors such as selumetinib (AZD6244, AR Y-142886), cobimetinib or GDC-0623 (see for example WO2015/0832840), Abl inhibitors such as imatinib or nilotinib, Btk inhibitors such as ibrutinib, Syk inhibitors such as fostamatinib, aurora kinase inhibitors (for example AZDl 152), inhibitors of other ser/thr kinases such as JAKs, STATs and IRAK4, and cyclin dependent kinase inhibitors;

iv) modulators of DNA damage signalling pathways, for example PARP inhibitors (e.g. Olaparib), ATR inhibitors or ATM inhibitors;

v) modulators of apoptotic and cell death pathways such as Bel family modulators (e.g. ABT-263 / Navitoclax, ABT-199);

(vi) antiangiogenic agents such as those which inhibit the effects of vascular endothelial growth factor, [for example the anti-vascular endothelial cell growth factor antibody bevacizumab (Avastin™) and for example, a VEGF receptor tyrosine kinase inhibitor such as sorafenib, axitinib, pazopanib, sunitinib and vandetanib (and compounds that work by other mechanisms (for example linomide, inhibitors of integrin ανβ3 function and angiostatin)];

(vii) vascular damaging agents, such as Combretastatin A4;

(viii) anti-invasion agents, for example c-Src kinase family inhibitors like (dasatinib, L Med. Chem.. 2004, 47, 6658-6661) and bosutinib (SKI-606), and metalloproteinase inhibitors like marimastat, inhibitors of urokinase plasminogen activator receptor function or antibodies to Heparanase];

(ix) immunotherapy approaches, including for example ex -vivo and in-vivo approaches to increase the immunogenicity of patient tumour cells, such as transfection with cytokines such as interleukin 2, interleukin 4 or granulocyte -macrophage colony stimulating factor, approaches to decrease T-cell anergy, approaches using transfected immune cells such as cytokine -transfected dendritic cells, approaches using cytokine-transfected tumour cell lines and approaches using anti-idiotypic antibodies. Specific examples include

monoclonal antibodies targeting PD-1 (e.g. BMS-936558 . PDL-1 or CTLA4 (e.g.

ipilimumab and tremelimumab);

(x) Antisense or RNAi based therapies, for example those which are directed to the targets listed.

(xi) gene therapy approaches, including for example approaches to replace aberrant genes such as aberrant p53 or aberrant BRCA1 or BRCA2, GDEPT (gene-directed enzyme pro-drug therapy) approaches such as those using cytosine deaminase, thymidine kinase or a bacterial nitroreductase enzyme and approaches to increase patient tolerance to chemotherapy or radiotherapy such as multi-drug resistance gene therapy.

According to this aspect there is provided a combination suitable for use in the treatment of cancer comprising a compound of Formula (I) as defined hereinbefore or a pharmaceutically-acceptable salt thereof and another anti-tumour agent, in particular any one of the anti tumour agents listed under (i) - (xi) above. In particular, the anti-tumour agent listed under (i)-(xi) above is the standard of care for the specific cancer to be treated; the person skilled in the art will understand the meaning of "standard of care".

Therefore in a further aspect there is provided a compound of Formula (I) or a pharmaceutically-acceptable salt thereof in combination with another anti -tumour agent, in particular an anti-tumour agent selected from one listed under (i) - (xi) herein above.

According to a further aspect there is provided a pharmaceutical composition which comprises a compound of Formula (I) or a pharmaceutically-acceptable salt thereof in combination with an anti-tumour agent selected from one listed under (i) - (xi) herein above, in association with a pharmaceutically-acceptable diluent or carrier.

According to a further aspect there is provided a pharmaceutical composition which comprises a compound of Formula (I) or a pharmaceutically-acceptable salt thereof in combination with an anti-tumour agent selected from one listed under (i) - (xi) herein above, in association with a pharmaceutically-acceptable diluent or carrier for use in treating cancer.

According to another feature there is provided the use of a compound of the Formula (I) or a pharmaceutically-acceptable salt thereof in combination with an anti- tumour agent selected from one listed under (i) - (xi) herein above, in the manufacture of a medicament for use in cancer in a warm-blooded animal, such as man.

According to another feature, there is provided a method of treating cancer in a warm-blooded animal, such as man, in need of such treatment which comprises administering to said animal an effective amount of a compound of Formula (I) or a pharmaceutically-acceptable salt thereof in combination with an anti-tumour agent selected from one listed under (i) - (xi) herein above.

In a further aspect there is provided a compound of Formula (I) or a

pharmaceutically-acceptable salt thereof in combination with another anti-tumour agent, in particular an anti-tumour agent selected from one listed under (i) above. In a further aspect there is provided a combination suitable for use in the treatment of cancer comprising a compound of Formula (I) as defined hereinbefore or a

pharmaceutically-acceptable salt thereof and any one of the anti tumour agents listed under (i) above.

According to a further aspect there is provided a pharmaceutical composition which comprises a compound of Formula (I) or a pharmaceutically-acceptable salt thereof in combination with an anti-tumour agent selected from one listed under (i) herein above, in association with a pharmaceutically-acceptable diluent or carrier.

According to a further aspect there is provided a pharmaceutical composition which comprises a compound of Formula (I) or a pharmaceutically-acceptable salt thereof in combination with an anti-tumour agent selected from one listed under (i) herein above, in association with a pharmaceutically-acceptable diluent or carrier for use in treating cancer.

According to another feature there is provided the use of a compound of the Formula (I) or a pharmaceutically-acceptable salt thereof in combination with an anti- tumour agent selected from one listed under (i) herein above, in the manufacture of a medicament for use in cancer in a warm-blooded animal, such as man.

According to another feature, there is provided a method of treating cancer in a warm-blooded animal, such as man, in need of such treatment which comprises administering to said animal an effective amount of a compound of Formula (I) or a pharmaceutically-acceptable salt thereof in combination with an anti-tumour agent selected from one listed under (i) herein above.

In a further aspect there is provided a compound of Formula (I) or a

pharmaceutically-acceptable salt thereof in combination with another anti -tumour agent, in particular an anti-tumour agent selected from one listed under (iii) above.

In a further aspect there is provided a combination suitable for use in the treatment of cancer comprising a compound of Formula (I) as defined hereinbefore or a

pharmaceutically-acceptable salt thereof and any one of the anti tumour agents listed under (iii) above.

According to a further aspect there is provided a pharmaceutical composition which comprises a compound of Formula (I) or a pharmaceutically-acceptable salt thereof in combination with an anti-tumour agent selected from one listed under (iii) herein above, in association with a pharmaceutically-acceptable diluent or carrier. According to a further aspect there is provided a pharmaceutical composition which comprises a compound of Formula (I) or a pharmaceutically-acceptable salt thereof in combination with an anti-tumour agent selected from one listed under (iii) herein above, in association with a pharmaceutically-acceptable diluent or carrier for use in treating cancer.

According to another feature there is provided the use of a compound of the Formula (I) or a pharmaceutically-acceptable salt thereof in combination with an anti- tumour agent selected from one listed under (iii) herein above, in the manufacture of a medicament for use in cancer in a warm-blooded animal, such as man.

According to another feature, there is provided a method of treating cancer in a warm-blooded animal, such as man, in need of such treatment which comprises administering to said animal an effective amount of a compound of Formula (I) or a pharmaceutically-acceptable salt thereof in combination with an anti-tumour agent selected from one listed under (iii) herein above.

In one aspect, suitable examples of anti tumour agents listed in (iii) above are those agents which also act on MAPK kinsases, particularly on the RAS-RAF-MEK-ERK signaling cascade such as MEK inhibitors.

pharmaceutically-acceptable salt thereof and a MEK inhibitor, such as selumetinib (ARRY-142886).

In one aspect, the above combination of the compound of formula (I) and selumetinib (ARRY-142886) is suitable for use in the treatment of any cancer dependent on the MAPK pathway, such as NSCLC, pancreatic or CR cancer, optionally in combination with standard of care therapy.

The combination of a compound of Formula (I) and an anti-tumour agent listed in (iii) above, particularly another agent acting on MAPK kinases, particularly on the RAS- RAF-MEK-ERK signaling cascade such as MEK inhibitors / may be particularly useful in treating tumours with a higher prevalence of mutation in KRAS or BRAF.

Particular combinations of the invention comprise any one of the compounds of the Examples herein (or a pharmaceutically-acceptable salt thereof) and a MEK inhibitor such as selumetinib (ARRY-142886) as described hereinabove. Further illustrative examples for combinations of the invention and a MEK inhibitor such as selumetinib (ARRY-14288) are:

(5)-3-methyl-2-((l-methyl-lH-l,2,3-triazol-5-yl)methyl)-7-(5-methyl-2-((l-methyl-lH- pyrazol-5-yl)amino)pyridin-4-yl)-3,4-dihydropyrrolo[l,2-a]pyrazin-l(2H)-one; and (5)-3-methyl-2-((l-methyl-lH-l,2,3-triazol-4-yl)methyl)-7-(5-methyl-2-((l-methyl-lH- pyrazol-5-yl)amino)pyridin-4-yl)-3,4-dihydropyrrolo[l,2-a]pyrazin-l(2H)-one.

In all of the above combinations, it will be understood that the combination may also be dosed with standard of care treatment, as understood by the skilled person, such as other treatments from (i) to (xi) hereinbefore. In other aspects, suitably the standard of care may be selected from (i) above.

Therefore in a further aspect of the invention, there is provided a triple combination suitable for use in the treatment of cancer

a) a compound of formula (I) or a pharmaceutically-acceptable salt thereof;

b) a compound selected from (iii) above (such as another compound acting on MAPK kinases) or a pharmaceutically-acceptable salt thereof; and

c) standard of care therapy for the cancer to be treated.

Suitably standard of care therapy may be dosed according to its usual dosing regimen, as understood by the skilled person.

According to a further aspect there is provided a kit comprising a compound of Formula (I) or a pharmaceutically-acceptable salt thereof in combination with an anti- tumour agent selected from one listed under (i) - (xi) herein above.

According to a further aspect there is provided a kit comprising:

a) a compound of Formula (I) or a pharmaceutically-acceptable salt thereof in a first unit dosage form; b) an anti-tumour agent selected from one listed under (i) - (xi) herein above in a second unit dosage form; and

c) container means for containing said first and second dosage forms.

According to a further aspect there is provided a kit comprising:

a) a compound of Formula (I) or a pharmaceutically-acceptable salt thereof in a first unit dosage form;

b) an anti-tumour agent selected from one listed under (i) - (xi) herein above in a second unit dosage form;

c) container means for containing said first and second dosage forms; and optionally d) instructions for use.

Herein, where the term "combination" is used it is to be understood that this refers to simultaneous, separate or sequential administration. In one aspect of the invention "combination" refers to simultaneous administration. In another aspect of the invention "combination" refers to separate administration. In a further aspect of the invention "combination" refers to sequential administration. Where the administration is sequential or separate, the delay in administering the second component should not be such as to lose the beneficial effect.

Although the compounds of the Formula (I) are primarily of value as therapeutic agents for use in warm-blooded animals (including man), they are also useful whenever it is required to inhibit ER . Thus, they are useful as pharmacological standards for use in the development of new biological tests and in the search for new pharmacological agents.

Personalised Healthcare

Another aspect of the present invention is based on identifying a link between the status of the gene encoding KRAS and susceptibility to treatment with a compound of Formula (I). This therefore provides opportunities, methods and tools for selecting patients for treatment with a compound of Formula (I), particularly cancer patients, and/or avoiding treatment of patients less likely to respond therapeutically to the treatment thus avoiding unnecessary treatment and any side effects that may be associated with such ineffective treatment.

The present invention relates to patient selection tools and methods (including personalised medicine). The selection is based on whether the tumour cells to be treated possess wild-type or mutant KRAS gene. The KRAS gene status can therefore be used as a biomarker of susceptibility to treatment with an ERK inhibitor.

There is a clear need for biomarkers that will enrich for or select patients whose tumours will respond to treatment with an ERK inhibitor, such as a compound of Formula (I). Patient selection biomarkers that identify the patients most likely to respond to an agent are ideal in the treatment of cancer, since they reduce the unnecessary treatment of patients with non-responding tumours to the potential side effects of such agents.

A biomarker can be described as "a characteristic that is objectively measured and evaluated as an indicator of normal biologic processes, pathogenic processes, or pharmacologic responses to a therapeutic intervention". A biomarker is any identifiable and measurable indicator associated with a particular condition or disease where there is a correlation between the presence or level of the biomarker and some aspect of the condition or disease (including the presence of, the level or changing level of, the type of, the stage of, the susceptibility to the condition or disease, or the responsiveness to a drug used for treating the condition or disease). The correlation may be qualitative, quantitative, or both qualitative and quantitative. Typically a biomarker is a compound, compound fragment or group of compounds. Such compounds may be any compounds found in or produced by an organism, including proteins (and peptides), nucleic acids and other compounds.

Biomarkers may have a predictive power, and as such may be used to predict or detect the presence, level, type or stage of particular conditions or diseases (including the presence or level of particular microorganisms or toxins), the susceptibility (including genetic susceptibility) to particular conditions or diseases, or the response to particular treatments (including drug treatments). It is thought that biomarkers will play an increasingly important role in the future of drug discovery and development, by improving the efficiency of research and development programs. Biomarkers can be used as diagnostic agents, monitors of disease progression, monitors of treatment and predictors of clinical outcome. For example, various biomarker research projects are attempting to identify markers of specific cancers and of specific cardiovascular and immunological diseases. It is believed that the development of new validated biomarkers will lead both to significant reductions in healthcare and drug development costs and to significant improvements in treatment for a wide variety of diseases and conditions. In order to optimally design clinical trials and to gain the most information from these trials, a biomarker may be required. The marker may be measurable in surrogate and tumour tissues. Ideally these markers will also correlate with efficacy and thus could ultimately be used for patient selection.

Thus, the technical problem underlying this aspect of the present invention is the identification of means for stratification of patients for treatment with a compound of Formula (I). The technical problem is solved by provision of the embodiments

characterized in the claims and/or description herein.

The invention provides a method of determining sensitivity of cells to a compound of Formula (I). The method comprises determining the status of KRAS gene in said cells. The cells are identified as likely to be sensitive to a compound of Formula I if the cells possess a mutated KRAS gene. Those patients with a mutated KRAS gene are therefore predicted to be particularly susceptible to treatment with a compound of Formula (I). A cell is defined as sensitive to a compound of Formula (I) if it inhibits the increase in cell number in a cell growth assay (either through inhibition of cell proliferation and /or through increased cell death). Methods of the invention are useful for predicting which cells are more likely to respond to a compound of Formula (I) by growth inhibition.

The present invention is further based, in part, on methods that can be used to determine a patient's responsiveness to a compound of Formula (I) including determining whether to administer a compound of Formula (I). Specifically the methods of the present invention include the determination of the gene status of KRAS. The presence of a mutated KRAS gene indicates that the tumour cells are more likely to respond by growth inhibition when contacted with a compound of Formula (I). The KRAS gene status can therefore be used to select patients for treatment with a compound of Formula (I).

A sample "representative of the tumour" can be the actual tumour sample isolated, or may be a sample that has been further processed, e.g. a sample of PCR amplified nucleic acid from the tumour sample.

Definitions:

In this Personalised Healthcare section:

"Allele" refers to a particular form of a genetic locus, distinguished from other forms by its particular nucleotide or amino acid sequence. "Amplification reactions" are nucleic acid reactions which result in specific amplification of target nucleic acids over non-target nucleic acids. The polymerase chain reaction (PCR) is a well known amplification reaction.

"Cancer" is used herein to refer to neoplastic growth arising from cellular transformation to a neoplastic phenotype. Such cellular transformation often involves genetic mutation.

"Gene" is a segment of DNA that contains all the information for the regulated biosynthesis of an R A product, including a promoter, exons, introns, and other sequence elements which may be located within 5 ' or 3 ' flanking regions (not within the transcribed portions of the gene) that control expression.

"Gene status" refers to whether the gene is wild type or not (i.e. mutant).

"Label" refers to a composition capable of producing a detectable signal indicative of the presence of the target polynucleotide in an assay sample. Suitable labels include radioisotopes, nucleotide chromophores, enzymes, substrates, fluorescent molecules, chemiluminescent moieties, magnetic particles, bioluminescent moieties, and the like. As such, a label is any composition detectable by spectroscopic, photochemical, biochemical, immunochemical, electrical, optical or chemical means.

"Non-synonymous variation" refers to a variation (variance) in or overlapping the coding sequence of a gene that result in the production of a distinct (altered) polypeptide sequence. These variations may or may not affect protein function and include missense variants (resulting in substitution of one amino acid for another), nonsense variants (resulting in a truncated polypeptide due to generation of a premature stop codon) and insertion/deletion variants.

"Synonymous variation" refers to a variation (variance) in the coding sequence of a gene that does not affect sequence of the encoded polypeptide. These variations may affect protein function indirectly (for example by altering expression of the gene), but, in the absence of evidence to the contrary, are generally assumed to be innocuous.

"Nucleic acid" refers to single stranded or double stranded DNA and RNA molecules including natural nucleic acids found in nature and/or modified, artificial nucleic acids having modified backbones or bases, as are known in the art.

"Primer" refers to a single stranded DNA oligonucleotide sequence capable of acting as a point of initiation for synthesis of a primer extension product which is complementary to the nucleic acid strand to be copied. The length and sequence of the primer must be such that they are able to prime the synthesis of extension products. A typical primer contains at least about 7 nucleotides in length of a sequence substantially complementary to the target sequence, but somewhat longer primers are preferred. Usually primers contain about 15-26 nucleotides, but longer or shorter primers may also be employed.

"Polymorphic site" is a position within a locus at which at least two alternative sequences are found in a population.

"Polymorphism" refers to the sequence variation observed in an individual at a polymorphic site. Polymorphisms include nucleotide substitutions, insertions, deletions and microsatellites and may, but need not, result in detectable differences in gene expression or protein function. In the absence of evidence of an effect on expression or protein function, common polymorphisms, including non-synonomous variants, are generally considered to be included in the definition of wild-type gene sequence. A catalog of human polymorphisms and associated annotation, including validation, observed frequencies, and disease association, is maintained by NCBI (dbSNP:

http://www.ncbi.nlm.nih.gov/proiects/SNP/). Please note that the term "polymorphism" when used in the context of gene sequences should not be confused with the term

"polymorphism" when used in the context of solid state form of a compound, that is the crystalline or amorphous nature of a compound. The skilled person will understand the intended meaning by its context.

"Probe" refers to single stranded sequence-specific oligonucleotides which have a sequence that is exactly complementary to the target sequence of the allele to be detected.

"Response" is defined by measurements taken according to Response Evaluation Criteria in Solid Tumours (RECIST) involving the classification of patients into two main groups: those that show a partial response or stable disease and those that show signs of progressive disease.

"Stringent hybridisation conditions" refers to an overnight incubation at 42°C in a solution comprising 50% formamide, 5x SSC (750 mM NaCI, 75 mM trisodium citrate), 50 mM sodium phosphate (pH 7.6), 5x Denhardt's solution, 10%> dextran sulphate, and 20 pg/ml denatured, sheared salmon sperm DNA, followed by washing the filters in O.lx SSC at about 65°C. "Survival" encompasses a patients' overall survival and progression-free survival.

"Overall survival" (OS) is defined as the time from the initiation of drug administration to death from any cause. "Progression-free survival" (PFS) is defined as the time from the initiation of drug administration to first appearance of progressive disease or death from any cause.

According to one aspect, the invention provides a method for selecting a cancer patient suitable for treatment with a compound of Formula (I), the method comprising;

(a) testing a cancer patient to determine whether the KRAS gene in the patient's tumour is wild type or mutant; and selecting a patient for treatment with a compound of Formula (I) based thereon.

In one embodiment, the status of the KRAS gene in a patient's tumour is determining from a biological sample obtained from said patient In one embodiment the biological sample is a tumour cell containing sample. In one embodiment the biological sample is one that contains tumour DNA, such as a blood sample. According to one aspect of the invention there is provided a method for selecting a patient for treatment with a compound of Formula (I), the method comprising obtaining a sample from a patient that comprises tumour cells or nucleic acid from the tumour cell; determining whether the KRAS gene in the patient's tumour cells is wild type or mutant; and selecting a patient for treatment with a compound of Formula (I) based thereon.

The method may include or exclude the actual patient sample isolation step. Thus, according to one aspect of the invention there is provided a method for selecting a patient for treatment with a compound of Formula (I), the method comprising determining whether the KRAS gene in a tumour cell or nucleic acid containing sample previously isolated from the patient is wild type or mutant; and selecting a patient for treatment with a compound of Formula (I) based thereon.

In one embodiment, the patient is selected for treatment with a compound of Formula (I) if the tumour cell has a mutant KRAS gene.

According to another aspect of the invention there is provided a method for predicting a patient's responsiveness to a compound of Formula (I), the method comprising determining whether the KRAS gene in the patient's tumour cells is wild type or mutant and based thereon, predicting a patient's responsiveness to treatment with a compound of Formula (I). According to another aspect of the invention there is provided a method for determining the likelihood of effectiveness of treatment with a compound of formula I in a human patient affected with cancer comprising: determining whether the KRAS gene(s) in the patient's tumour cells is wild type or mutant and based thereon, predicting a patient's responsiveness to treatment with a compound of Formula (I).

For the purpose of this invention, a gene status of wild-type is meant to indicate normal or appropriate expression of the gene and normal function of the encoded protein. In contrast, mutant status is meant to indicate abnormal or inappropriate gene expression, or expression of a protein with altered function, consistent with the known roles of mutant KRAS in cancer (as described herein). Any number of genetic or epigenetic alterations, including but not limited to mutation, amplification, deletion, genomic rearrangement, or changes in methylation profile, may result in a mutant status. However, if such alterations nevertheless result in appropriate expression of the normal protein, or a functionally equivalent variant, then the gene status is regarded as wild-type. Examples of variants that typically would not result in a functional mutant gene status include synonomous coding variants and common polymorphisms (synonymous or non-synonymous). As discussed below, gene status can be assessed by a functional assay, or it may be inferred from the nature of detected deviations from a reference sequence.

In certain embodiments the wild-type or mutant status of the KRAS gene is determined by the presence or absence of non-synonymous nucleic acid variations in the genes. Observed non-synonymous variations corresponding to known common polymorphisms with no annotated functional effects do not contribute to a gene status of mutant.

KRAS Gene bank accession details: KRAS NM 004985

It will be apparent that the gene and mRNA sequences disclosed for KRAS and the KRAS protein sequence are each a representative sequence. In normal individuals there are two copies of each gene, a maternal and paternal copy, which will likely have some sequence differences, moreover within a population there will exist numerous allelic variants of the gene sequence. Other sequences regarded as wild type include those that possess one or more synonymous changes to the nucleic acid sequence (which changes do not alter the encoded protein sequence), non-synonymous common polymorphisms (e.g. germ-line polymorphisms) which alter the protein sequence but do not affect protein function, and intronic non-splice-site sequence changes.

According to another aspect of the invention there is provided a method for determining the likelihood of effectiveness of treatment with a compound of Formula (I) in a human patient affected with cancer comprising: detecting the presence or absence of at least one non-synonymous nucleic acid variance in the KRAS gene of said patient relative to the wild type gene, wherein the presence of at least one somatic non-synonymous nucleic acid variance in the KRAS gene indicates that treatment with the compound of Formula (I) is likely to be effective.

According to another aspect of the invention there is provided a method for assessing the susceptibility of an individual to treatment with a compound of Formula (I), which method comprises:

(i) determining the non-synonymous mutation status of the KRAS gene in tumour cell nucleic acid from the individual; and,

(ii) determining the likely susceptibility of the individual to treatment with a compound of Formula (I) by reference to the non-synonymous mutation status of the KRAS gene in the tumour cells.

There are numerous techniques available to the person skilled in the art to determine the gene status of KRAS. The gene status can be determined by determination of the nucleic acid sequence. This could be via direct sequencing of the full-length gene or analysis of specific sites within the gene, e.g. commonly mutated sites.

An alternative means for determining whether or not the KRAS gene is wild type or mutant is to assess the function of the transcribed gene. Functional mutation of this KRAS gene produces a protein that has impaired GTP hydrolysis capability. Mutant KRAS persists in an active, GTP-bound state, leading to constitutive and deregulated stimulation of downstream signalling of the pathway in cells, including but not limited to activation of Raf, PI3K and Ral pathways.

The assays to assess the functional status of KRAS variants when expressed in cells include but are not limited to:

(i) increased binding to the Ras binding domain (RBD) of Rafl

(ii) increased levels of phosphorylated ERK1/2, MEK1/2, or Akt; (iii) increased focus and colony formation of NIH-3T3 cells transfected with the variant of KRAS

Samples

The patient's sample to be tested for the gene status can be any tumour tissue, tumour-cell containing or tumour nucleic acid containing sample obtained or obtainable from the individual. The test sample is conveniently a sample of blood, mouth swab, biopsy, or other body fluid or tissue obtained from an individual. Particular examples include: circulating tumour cells, circulating DNA in the plasma or serum, cells isolated from the ascites fluid of ovarian cancer patients, lung sputum for patients with tumours within the lung, a fine needle aspirate from a breast cancer patient, urine, peripheral blood, a cell scraping, a hair follicle, a skin punch or a buccal sample.

It will be appreciated that the test sample may equally be a nucleic acid sequence corresponding to the sequence in the test sample, that is to say that all or a part of the region in the sample nucleic acid may firstly be amplified using any convenient technique e.g. polymerase chain reaction (PCR), before analysis. The nucleic acid may be genomic DNA or fractionated or whole cell RNA. In particular embodiments the RNA is whole cell RNA and is used directly as the template for labelling a first strand cDNA using random primers or poly A primers. The nucleic acid or protein in the test sample may be extracted from the sample according to standard methodologies (see Green & Sambrook, Eds., Molecular Cloning: A Laboratory Manual, (2012, 4th edition, Vol. 1-3, ISBN

9781936113422), Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y.).

The diagnostic methods of the invention can be undertaken using a sample previously taken from the individual or patient. Such samples may be preserved by freezing or fixed and embedded in formalin-paraffin or other media. Alternatively, a fresh tumour cell containing sample may be obtained and used.

The methods of the invention can be applied using cells from any tumour. Suitable tumours for treatment with a compound of Formula (I) have been described hereinbefore.

Methods for Detection of Nucleic Acids

The detection of mutant KRAS nucleic acids can be employed, in the context of the present invention, to predict the response to drug treatment. Since mutations in these genes occur at the DNA level, the methods of the invention can be based on detection of mutations or variances in genomic DNA, as well as transcripts and proteins themselves. It can be desirable to confirm mutations in genomic DNA by analysis of transcripts and/or polypeptides, in order to ensure that the detected mutation is indeed expressed in the subject.

It will be apparent to the person skilled in the art that there are a large number of analytical procedures which may be used to detect the presence or absence of variant nucleotides at one or more positions in a gene. In general, the detection of allelic variation requires a mutation discrimination technique, optionally an amplification reaction (such as one based on polymerase chain reaction) and optionally a signal generation system. There are a multitude of mutation detection techniques available in the art and these may be used in combination with a signal generation system, of which there are numerous available in the art. Many methods for the detection of allelic variation are reviewed by Nollau et al, Clin. Chem., 1997, 43, 1114-1120; Anderson SM. Expert Rev Mol Diagn., 2011, 11, 635- 642; Meyerson M. et al, Nat Rev Genet., 2010, H, 685-696; and in standard textbooks, for example "Laboratory Protocols for Mutation Detection", Ed. by U. Landegren, Oxford University Press, 1996 and "PCR", 2^nd Edition by Newton & Graham, BIOS Scientific Publishers Limited, 1997.

As noted above, determining the presence or absence of a particular variance or plurality of variances in the KRAS gene in a patient with cancer can be performed in a variety of ways. Such tests are commonly performed using DNA or RNA collected from biological samples, e.g., tissue biopsies, urine, stool, sputum, blood, cells, tissue scrapings, breast aspirates or other cellular materials, and can be performed by a variety of methods including, but not limited to, PCR, hybridization with allele-specific probes, enzymatic mutation detection, chemical cleavage of mismatches, mass spectrometry or DNA sequencing, including minisequencing.

Suitable mutation detection techniques include amplification refractory mutation system (ARMS™), amplification refractory mutation system linear extension (ALEX™), competitive oligonucleotide priming system (COPS), Taqman, Molecular Beacons, restriction fragment length polymorphism (RFLP), and restriction site based PCR and fluorescence resonance energy transfer (FRET) techniques. In particular embodiments the method employed for determining the nucleotide(s) within a biomarker gene is selected from: allele-specific amplification (allele specific PCR) - such as amplification refractory mutation system (ARMS), sequencing, allelic discrimination assay, hybridisation, restriction fragment length polymorphism (RFLP) or oligonucleotide ligation assay (OLA).

Generation of nucleic acids for analysis from samples generally requires nucleic acid amplification. Many amplification methods rely on an enzymatic chain reaction (such as a polymerase chain reaction, a ligase chain reaction, or a self-sustained sequence replication) or from the replication of all or part of the vector into which it has been cloned. Preferably, the amplification according to the invention is an exponential amplification, as exhibited by for example the polymerase chain reaction.

Many target and signal amplification methods have been described in the literature, for example, general reviews of these methods in Landegren, U. , et al, Science, 1988 242, 229-237 and Lewis, R., Genetic Engineering News 1990, 10, 54-55. These amplification methods can be used in the methods of our invention, and include polymerase chain reaction (PCR), PCR in situ, ligase amplification reaction (LAR), ligase hybridisation, QP bacteriophage replicase, transcription-based amplification system (TAS), genomic amplification with transcript sequencing (GAWTS), nucleic acid sequence-based amplification (NASBA) and in situ hybridisation. Primers suitable for use in various amplification techniques can be prepared according to methods known in the art.

Polymerase Chain Reaction (PCR) PCR is a nucleic acid amplification method described inter alia in U.S. Pat. Nos. 4,683,195 and 4,683,202. PCR consists of repeated cycles of DNA polymerase generated primer extension reactions. The target DNA is heat denatured and two oligonucleotides, which bracket the target sequence on opposite strands of the DNA to be amplified, are hybridised. These oligonucleotides become primers for use with DNA polymerase. The DNA is copied by primer extension to make a second copy of both strands. By repeating the cycle of heat denaturation, primer hybridisation and extension, the target DNA can be amplified a million fold or more in about two to four hours. PCR is a molecular biology tool, which must be used in conjunction with a detection technique to determine the results of amplification. An advantage of PCR is that it increases sensitivity by amplifying the amount of target DNA by 1 million to 1 billion fold in approximately 4 hours. PCR can be used to amplify any known nucleic acid in a diagnostic context (Mok et al, Gvnaecologic Oncology, 1994, 52: 247-252,).

An allele specific amplification technique such as Amplification Refractory Mutation System (ARMS™) (Newton et al, Nucleic Acids Res., 1989, 17, 2503-2516) can also be used to detect single base mutations. Under the appropriate PCR amplification conditions a single base mismatch located at the 3 '-end of the primer is sufficient for preferential amplification of the perfectly matched allele (Newton et al, 1989, supra), allowing the discrimination of closely related species. The basis of an amplification system using the primers described above is that oligonucleotides with a mismatched 3'-residue will not function as primers in the PCR under appropriate conditions. This amplification system allows genotyping solely by inspection of reaction mixtures after agarose gel electrophoresis.

Analysis of amplification products can be performed using any method capable of separating the amplification products according to their size, including automated and manual gel electrophoresis, mass spectrometry, and the like.

The methods of nucleic acid isolation, amplification and analysis are routine for one skilled in the art and examples of protocols can be found, for example, Green & Sambrook, Eds., Molecular Cloning: A Laboratory Manual, (2012, 4th edition, Vol. 1-3, ISBN 9781936113422), Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y.) Particularly useful protocol source for methods used in PCR amplification is PCR (Basics: From Background to Bench) by M. J. McPherson, S. G. Mailer, R. Beynon, C. Howe, Springer Verlag; 1st edition (October 15, 2000), ISBN: 0387916008.

According to another aspect of the invention there is provided the use of a compound of Formula (I) to treat a cancer patient whose tumour cells have been identified as possessing a mutant KRAS gene.

According to another aspect of the invention there is provided a compound of Formula (I) for treating cancers with tumour cells identified as harbouring mutant KRAS gene.

In still further embodiments, the invention relates to pharmaceutical composition comprising a compound of Formula (I) for use in the prevention and treatment of cancer with tumour cells identified as harbouring a mutant KRAS gene. For all the aspects above, mutant forms of KRAS determined/identified are at all positions across the gene.

In further aspects, compounds of the invention may also be useful in treating BRAF mutant cancers. The information provided above within this personalised Healthcare section for KRAS mutant cancers may analogously be applied to BRAF resistant cancers, other than Gene Bank Accession details. BRAF gene bank accession details:

BRAF NM 004333.

Examples

The invention will now be illustrated in the following Examples in which, generally:

(i) operations were carried out at ambient temperature, i.e. in the range 17 to 25 °C and under an atmosphere of an inert gas such as nitrogen unless otherwise stated;

(ii) evaporations were carried out by rotary evaporation or utilising Genevac equipment or Biotage vlO evaporator in vacuo and work-up procedures were carried out after removal of residual solids by filtration;

(iii) flash chromatography purifications were performed on an

automated Teledyne Isco CombiFlash® Rf or Teledyne Isco CombiFlash®

Companion® using prepacked RediSep Rf Gold™ Silica Columns (20-40 μιη, spherical particles), GraceResolv™ Cartridges (Davisil® silica) or Silicycle cartridges (40 - 63 μιη).

(iv) preparative chromatography was performed on a Gilson prep HPLC instrument with UV collection;

(v) chiral preparative chromatography was performed on a Gilson instrument with UV collection (233 injector / fraction collector, 333 & 334 pumps, 155 UV detector), or an Interchim PuriFlash 4250-250 system or a Novasep LC50 system with Knauer K2501 UV detector;

(vi) yields, where present, are not necessarily the maximum attainable;

(vii) in general, the structures of end-products of the Formula I were confirmed by nuclear magnetic resonance (NMR) spectroscopy; NMR chemical shift values were measured on the delta scale [proton magnetic resonance spectra were determined using a Bruker Avance 500 (500 MHz) or Bruker Avance 400 (400 MHz) instrument];

measurements were taken at ambient temperature unless otherwise specified; the following abbreviations have been used: s, singlet; d, doublet; t, triplet; q, quartet; m, multiplet; dd, doublet of doublets; ddd, doublet of doublet of doublet; dt, doublet of triplets; bs, broad signal. Where DMSO is the solvent used for obtaining an NMR spectrum it is assumed that this is hexadeuterodimethylsulfoxide.

(viii) in general, end-products of the Formula I were also characterised by mass spectroscopy following liquid chromatography (LCMS or UPLC); UPLC was carried out using a Waters UPLC fitted with Waters SQ mass spectrometer (Column temp 40, UV = 220-300nm, Mass Spec = ESI with positive/negative switching) at a flow rate of lml/min using a solvent system of 97% A + 3% B to 3% A to 97% B over 1.50mins (total runtime with equilibration back to starting conditions etc 1.70min), where A = 0.1% formic acid in water (for acid work) or 0.1% ammonia in water (for base work) B = acetonitrile. For acid analysis the column used was Waters Acquity HSS T3 1.8μιη 2.1 x50 mm, for base analysis the column used was Waters Acquity BEH 1.7μιη 2.1x50mm; LCMS was carried out using a Waters Alliance HT (2795) fitted with a Waters ZQ ESCi mass spectrometer and a Phenomenex Gemini -NX (50x2. lmm 5μιη) column at a flow rate of 1.lml/min 95 %A to 95 %B over 4 min with a 0.5 min hold. The modifier is kept at a constant 5% C (50:50 acetonitrile: water 0.1% formic acid) or D (50:50 acetonitrile: water 0.1% ammonium hydroxide (0.88 SG) depending on whether it is an acidic or basic method.

(ix) ion exchange purification was generally performed using a SCX-2 (Biotage, Propylsulfonic acid functionalized silica. Manufactured using a trifunctional silane. Non end-capped) cartridge.

(x) intermediate purity was assessed by thin layer chromatographic, mass spectral, HPLC (high performance liquid chromatography) and/or NMR analysis;

(xi) the following abbreviations have been used:-

Boc tert-Butoxycarbonyl

CDCb deutero-chloroform

DCM dichloromethane

DMF N,N-dimethylformamidc

DMSO dimethyl sulphoxide

EtOAc ethyl acetate

iPr isopropyl MeOH methanol

MTBE methyl tert-butyl ether

THF tetrahydrofuran

TFA trifluoroacetic acid

Example 1

(S)-3-Methyl-7-(5-methyl-2-((l-methyl-lH-pyrazol-5-yl)amino)pyridin-4-yl)-2-((6- meth lpyrimidin-4-yl)methyl)-3,4-dihydropyrrolo [ 1 ,2-a] pyrazin- 1 (2H)-one

[(2-Di-cyclohexylphosphino-3,6-dimethoxy-2',4',6'- triisopropyl-l, -biphenyl)-2-(2'- amino-Ι, -biphenyl)]palladium(II) methanesulfonate (26.1 mg, 0.03 mmol) was added to (5)-7-(2-chloro-5-methylpyridin-4-yl)-3-methyl-2-((6-methylpyrimidin-4-yl)methyl)-3,4- dihydropyrrolo[l,2-a]pyrazin-l(2H)-one (Intermediate 1; 110 mg, 0.29 mmol), 1-methyl- lH-pyrazol-5-amine (69.9 mg, 0.72 mmol) and cesium carbonate (188 mg, 0.58 mmol) in 1,4-dioxane (8 mL) at 25 °C under nitrogen. The resulting mixture was stirred at 120 °C for 8 hours. The solvent was removed under reduced pressure. The crude product was purified by flash silica chromatography (elution gradient 0 to 6% MeOH in DCM). Pure fractions were evaporated to dryness to afford a residue. This residue was purified further by preparative HPLC (XSelect CSH Prep C18 OBD column, 5μ silica, 19 mm diameter, 150 mm length), using decreasingly polar mixtures of water (containing 0.03% N¾) and MeCN as eluents. Fractions containing the desired compound were evaporated to dryness to afford (5)-3-methyl-7-(5-methyl-2-((l -methyl- lH-pyrazol-5-yl)amino)pyridin-4-yl)-2- ((6-methylpyrimidin-4-yl)methyl)-3,4-dihydropyrrolo[l,2-a]pyrazin-l(2H)-one (Example

1; 36.0 mg, 28.2 %) as a solid. ^lH NMR (400 MHz, DMSO, 23 °C) 1.19 - 1.21 (3H, d), 2.30 (3H, s), 2.47 (3H, s), 3.66 (3H, s), 3.93 - 3.97 (1H, m), 4.12 - 4.16 (1H, dd), 4.26 - 4.30 (1H, d), 4.49 - 4.50 (1H, d), 5.09 - 5.13 (1H, d), 6.21 - 6.22 (1H, d), 6.81 (1H, s), 6.93 - 6.94 (1H, d), 7.3 1 - 7.32 (1H, d), 7.39 - 7.42 (2H, m), 7.96 (1H, s), 8.52 (1H, s), 8.97 (1H, d). m/z (ES+), [M+H]+ = 443.

Intermediate 1

(S)-7-(2-Chloro-5-methylpyridin-4-yl)-3-methyl-2-((6-methylpyrimidin-4-yl)

3 4-dihydropyrrolo [ 1 ,2-a] pyrazin-1 (2H)-one

Trimethyl aluminium (0.785 mL, 1.57 mmol) was added to (5)-methyl 4-(2-chloro-5- methylpyridin-4-yl)- 1 -(2-(((6-methylpyrimidin-4-yl)methyl)amino)propyl)- lH-pyrrole-2- carboxylate (Intermediate 2; 130 mg, 0.31 mmol) in toluene (8 mL) at 25 °C under nitrogen and the resulting mixture was stirred at 90 °C for 12 hours. The reaction mixture was quenched with 2M NaOH (10 mL), extracted with DCM (3 x 25 mL), the organic layer was dried over Na₂S04, filtered and evaporated to afford a residue. The crude product was purified by flash silica chromatography (elution gradient 0 to 4% MeOH in DCM). Pure fractions were evaporated to dryness to afford (5)-7-(2-chloro-5-methylpyridin-4-yl)- 3-methyl-2-((6-methylpyrimidin-4-yl)methyl)-3,4-dihydropyrrolo[l,2-a]pyrazin-l(2H)-one (Intermediate 1; 110 mg, 92 %) as a solid, m/z (ES+), [M+H]+ = 382.

Intermediate 2

(S)-Methyl 4-(2-chloro-5-methylpyridin-4-yl)-l-(2-(((6-methylpyrimidin-4- l)methyl)amino)propyl)-lH-pyrrole-2-carboxylate

6-methylpyrimidine-4-carbaldehyde (96 mg, 0.79 mmol) was added to (5)-methyl l-(2- aminopropyl)-4-(2-chloro-5-methylpyridin-4-yl)-lH-pyrrole-2-carboxylate

dihydrochloride (Intermediate 3; 250 mg, 0.66 mmol) in DCM (10 mL) at 25 °C under nitrogen. After stirring at 40 °C for 3 hours sodium triacetoxyborohydride (278 mg, 1.31 mmol) was added. The resulting mixture was stirred at 25 °C for 12 hours. The reaction mixture was quenched with saturated NaHC0₃ (10 mL), extracted with DCM (2 x 50 mL), the organic layer was dried over Na₂S04, filtered and evaporated to afford a residue. The crude product was purified by flash silica chromatography (elution gradient 0 to 5% MeOH in DCM). Pure fractions were combined and evaporated to dryness to afford (S)- methyl 4-(2-chloro-5-methylpyridin-4-yl)-l -(2-(((6-methylpyrimidin-4- yl)methyl)amino)propyl)-lH-pyrrole-2-carboxylate (Intermediate 2; 130 mg, 47.8 %) as a solid. ^!H NMR (400 MHz, CDC1 , 24 °C) 1.43 - 1.72 (6H, m), 2.43 (3H, d), 2.56 (3H, d), 3.81 - 3.91 (3H, m), 4.70 (2H, d), 7.17 (1H, s), 7.25-7.28 (1H, m), 7.35 (1H, s), 7.51 (1H, s), 8.24 (1H, s), 8.94 (1H, s). m/z (ES+), [M+H]+ = 414 .

Intermediate 3

(S)-Methyl-l-(2-aminopropyl)-4-(2-chloro-5-methylpyridin-4-yl)-lH-pyrrole-2- carbox late dihydrochloride

4N Hydrochloric acid in 1 ,4-dioxane (25 mL) was added to (5)-methyl l-(2-((tert- butoxycarbonyl)amino)propyl)-4-(2-chloro-5-methylpyridin-4-yl)-lH-pyrrole-2- carboxylate (Intermediate 4; 1.64 g, 4.02 mmol) under air. The resulting solution was stirred at 20 °C for 12 hours. The precipitate was collected by filtration, washed with DCM (20 mL) and dried under vacuum to afford (5)-methyl l-(2-aminopropyl)-4-(2-chloro-5- methylpyridin-4-yl)-lH-pyrrole-2-carboxylate (Intermediate 3; 1.44 g, 94%) as a solid. ^!H NMR (400 MHz, DMSO, 21.4°C) 1.21 (3H, d), 2.41 (3H, s), 3.60 - 3.64 (1H, m), 3.81 (3H, s), 4.49 - 4.64 (2H, m), 7.40 (1H, d), 7.59 (1H, s), 7.89 (3H, d), 8.24 (1H, s), 8.46 (2H, s). m/z (ES+), [M+H]+ 308.

Intermediate 4

(S)-Methyl-l-(2-((tei"i-butoxycarbonyl)amino)propyl)-4-(2-chloro-5-methylpyridin-4- l)- lH-pyrrole-2-carboxylate

Potassium carbonate (9.37 g, 67.82 mmol) was added to (S)-tert-butyl 4-methyl-l,2,3- oxathiazolidine-3-carboxylate 2,2-dioxide (Intermediate 5; 4.83 g, 20.34 mmol), methyl 4- (2-chloro-5-methylpyridin-4-yl)-lH-pyrrole-2-carboxylate (Intermediate 7; 3.4 g, 13.56 mmol) and 1,4,7, 10,13, 16-hexaoxacyclooctadecane (0.896 g, 3.39 mmol) in 1,4- dioxane (100 mL) at 22 °C under nitrogen. The resulting mixture was stirred at 100 °C. The hot reaction mixture was filtered through a layer of celite, washed with DCM and evaporated to afford (5)-methyl l-(2-((tert-butoxycarbonyl)amino)propyl)-4-(2-chloro-5- methylpyridin-4-yl)-lH-pyrrole-2-carboxylate (Intermediate 4; 5.53 g, 100%) as a solid. m/z (ES+), [M+H]+ = 408.

Intermediate 7

Meth l 4-(2-chloro-5-methylpyridin-4-yl)-lH-pyrrole-2-carboxylate

TFA (30 mL, 389.39 mmol) was added to 1-ieri-butyl 2-methyl 4-(2-chloro-5- methylpyridin-4-yl)-lH-pyrrole-l,2-dicarboxylate (Intermediate 8; 7.5 g, 21.38 mmol) in DCM (60 mL) at 20 °C. The resulting solution was stirred at 20 °C for 12 hours. The solvent was removed under reduced pressure. The reaction mixture was adjusted to pH 7-8 with saturated NaHC0₃. The resultant precipitate was collected by filtration, washed with water (100 mL) and dried under vacuum to afford methyl 4-(2-chloro-5-methylpyridin-4- yl)-lH-pyrrole-2-carboxylate (Intermediate 7; 4.70 g, 88 %) as a white solid, which was used without further purification, m/z (ES+), [M+H]+ = 251.

Intermediate 8

1-terf-But l 2-methyl 4-(2-chloro-5-methylpyridin-4-yl)- IH-pyrrole- 1 ,2-dicarboxylate

Pd(Ph₃P)₄ (2.80 g, 2.42 mmol) was added to 1-tert-butyl 2-methyl 4-(4,4,5,5-tetramethyl- l,3,2-dioxaborolan-2-yl)-lH-pyrrole-l,2-dicarboxylate (17.01 g, 48.43 mmol), 4-bromo-2- chloro-5-methylpyridine (10 g, 48.43 mmol) and Na₂C0₃ (10.27 g, 96.87 mmol) in 1,4- dioxane (150 mL),water (30 mL) at 20 °C under nitrogen. The resulting solution was stirred at 80 °C for 4 hours. The reaction mixture was poured into water (200 mL), extracted with EtOAc (3 x 200 mL), the organic layer was dried over Na₂S0₄, filtered and evaporated to afford yellow oil. The crude product was purified by flash silica

chromatography (elution gradient 9 to 10% EtOAc in petroleum ether). Pure fractions were evaporated to dryness to afford l-tert-butyl 2-methyl 4-(2-chloro-5-methylpyridin-4-yl)- lH-pyrrole-l,2-dicarboxylate (Intermediate 8; 7.80 g, 45.9%) as a colourless oil. ^!Η NMR (300 MHz, CDC1 ) δ 1.64 (9H, s), 2.41 (3H, s), 3.91 (3H, s), 7.05 (1H, s), 7.32 (1H, s), 7.55 (1H, s), 8.25 (1H, s). m/z (ES+), [M+H]+ = 351. Intermediate 5

(S -tert-Buty\ 4-methyl-l,2,3-oxathiazolidine-3-carboxylate 2,2-dioxide

Ruthenium(III) chloride hydrate (0.062 g, 0.28 mmol) was added to a stirred mixture of tert-butyl (45)-4-methyl-2-oxido-oxathiazolidin-2-ium-3-carboxylate (Intermediate 6; 87.36 g, 394.80 mmol) in acetonitrile (778 ml) and water (419 ml) at 15 °C, followed by portion wise addition of sodium periodate (93 g, 434.29 mmol). The biphasic mixture was stirred at 20 °C for 1 hour. Water (600 mL) was added and the mixture extracted into ethyl acetate (3 x 600 mL). The combined organics were washed with water (500 mL), brine (250 mL), dried over MgS0₄, filtered and concentrated in vacuo to give ( -tert-butyl 4- methyl-l,2,3-oxathiazolidine-3-carboxylate 2,2-dioxide (Intermediate 5; 84.3 g, 355 mmol, 90%) as an off-white solid. ^!H NMR (400 MHz, CDCb, 30 °C) 1.51 (3H, d), 1.55 (9H, s), 4.19 (1H, dd), 4.37 - 4.46 (1H, m), 4.66 (1H, dd).

Intermediate 6

tert- ut l (4S)-4-methyl-2-oxido-oxathiazolidin-2-ium-3-carboxylate

To a solution of lH-imidazole (106 g, 1553.20 mmol) and triethylamine (124 ml, 893.09 mmol) in anhydrous dichloromethane (1427 ml) at -55 °C was added thionyl chloride (32.6 ml, 446.54 mmol) dropwise. The mixture was stirred for 5 minutes while cooling to - 60 °C and a solution of (S)-tert-butyl 1 -hydroxypropan-2-ylcarbamate (68.04 g, 388.30 mmol) in anhydrous dichloromethane (1427 mL) was added dropwise over 3.5 hours. The mixture was stirred while warming to room temperature overnight. Water was added (750 mL) and the phases separated. The aqueous phase was further extracted into

dichloromethane (500 mL). The combined organics were washed with water (250 mL), saturated brine (250 mL), dried over MgS0₄, filtered and concentrated in vacuo to give tert-butyl (45)-4-methyl-2-oxido-oxathiazolidin-2-ium-3-carboxylate (Intermediate 18; 87.3 g, 100%) as a pale yellow oil. ^lH NMR (400 MHz, CDCb, 30 °C) 1.50 (3H d), 4.29 (1H, d), 4.68 (1H, t), 4.77 (1H, dd).

Example 2

(S)-3-Methyl-7-(5-methyl-2-((l-methyl-lH-pyrazol-5-yl)amino)pyridin-4-yl)-2-((2- meth lpyrimidin-4-yl)methyl)-3,4-dihydropyrrolo [ 1 ,2-a] pyrazin- 1 (2H)-one

[(2-Di-cyclohexylphosphino-3,6-dimethoxy-2',4',6'- triisopropyl-l, -biphenyl)-2-(2'- amino-Ι, -biphenyl)]palladium(II) methanesulfonate (18.99 mg, 0.02 mmol) was added to (5)-7-(2-chloro-5-methylpyridin-4-yl)-3-methyl-2-((2-methylpyrimidin-4-yl)m

3,4-dihydropyrrolo[l,2-a]pyrazin-l(2H)-one (Intermediate 9; 80 mg, 0.21 mmol), 1- methyl-lH-pyrazol-5-amine (50.9 mg, 0.52 mmol) and cesium carbonate (137 mg, 0.42 mmol) in 1,4-dioxane (8 mL) at 25°C under nitrogen. The resulting mixture was stirred at 120 °C for 8 hours. The solvent was removed under reduced pressure. The crude product was purified by flash silica chromatography (elution gradient 0 to 6% MeOH in DCM). Pure fractions were combined and evaporated to dryness to afford a residue. The crude product was purified by preparative HPLC (XSelect CSH Prep C18 OBD column, 5μ silica, 19 mm diameter, 150 mm length), using decreasingly polar mixtures of water (containing 0.03% N¾) and MeCN as eluents. Fractions containing the desired compound were combined and evaporated to dryness to afford (S)-3 -methyl-7-(5 -methyl -2-((l- methyl- lH-pyrazol-5-yl)amino)pyridin-4-yl)-2-((2 -methylpyrimidin-4-yl)methyl)-3,4- dihydropyrrolo[ 1 ,2-a]pyrazin- 1 (2H)-one (Example 2; 17.00 mg, 18.34%) as a solid. ^!H NMR (400 MHz, DMSO, 30 °C) 1.20 (3H, d), 2.30 (3H, s), 2.61 (3H, s), 3.67 (3H, s), 4.00 (1H, ddd), 4.17 (1H, dd), 4.33 (1H, d), 4.38 - 4.5 (1H, m), 5.10 (1H, d), 6.21 (1H, d), 6.81 (1H, s), 6.94 (1H, d), 7.19 - 7.36 (2H, m), 7.41 (1H, d), 7.96 (1H, s), 8.48 (1H, s), 8.62 (1H, d). m/z (ES+), [M+H]+ = 443. Intermediate 9

(S)-7-(2-Chloro-5-methylpyridin-4-yl)-3-methyl-2-((2-methylpyrimidin-4-yl)

3 4-dihydropyrrolo [ 1 ,2-a] pyrazin-1 (2H)-one

Trimethyl aluminium (0.785 mL, 1.57 mmol) was added to (5)-methyl 4-(2-chloro-5- methylpyridin-4-yl)- 1 -(2-(((2-methylpyrimidin-4-yl)methyl)amino)propyl)- lH-pyrrole-2- carboxylate (Intermediate 10; 130 mg, 0.31 mmol) in toluene (8 mL) at 25°C under nitrogen. The resulting mixture was stirred at 90 °C for 12 hours. The reaction mixture was quenched with 2M NaOH (10 mL), extracted with DCM (3 x 25 mL), and dried over Na₂S04, filtered and evaporated to afford a residue. The crude product was purified by flash silica chromatography (elution gradient 0 to 4% MeOH in DCM). Pure fractions were evaporated to dryness to afford a solid (5)-7-(2-chloro-5-methylpyridin-4-yl)-3- methyl-2-((2-methylpyrimidin-4-yl)methyl)-3 ,4-dihydropyrrolo [ 1 ,2-a]pyrazin- 1 (2H)-one (Intermediate 9; 80 mg, 66.7%). m/z (ES+), [M+H]+ = 382.

Intermediate 10

(S)-Methyl 4-(2-chloro-5-methylpyridin-4-yl)-l-(2-(((2-methylpyrimidin-4- l)methyl)amino)propyl)-lH-pyrrole-2-carboxylate

2-methylpyrimidine-4-carbaldehyde (96 mg, 0.79 mmol) was added to (5)-methyl l-(2- aminopropyl)-4-(2-chloro-5-methylpyridin-4-yl)-lH-pyrrole-2-carboxylate

dihydrochloride (Intermediate 3; 250 mg, 0.66 mmol) in DCM (10 mL) at 25°C under nitrogen. After stirring at 40°C for 3 hours, sodium triacetoxyborohydride (278 mg, 1.31 mmol) was added. The resulting mixture was stirred at 25 °C for 12 hours. The reaction mixture was quenched with saturated NaHC0₃ (20 mL), extracted with DCM (3 x 50 mL) and dried over Na₂S04, filtered and evaporated to afford a residue. The crude product was purified by flash silica chromatography (elution gradient 0 to 5% MeOH in DCM). Pure fractions were evaporated to dryness to afford (5)-methyl 4-(2-chloro-5-methylpyridin-4- yl)- 1 -(2-(((2-methylpyrimidin-4-yl)methyl)amino)propyl)- 1 H-pyrrole-2-carboxylate (Intermediate 10; 130 mg, 47.8 %) as a solid, m/z (ES+), [M+H]+ = 414. Example 3

(S)-2-((l,3-Dimethyl-lH-l,2,4-triazol-5-yl)methyl)-3-methyl-7-(5-methyl-2-((l-methyl- lH-pyrazol-5-yl)amino)pyridin-4-yl)-3,4-dihydropyrrolo [ 1 ,2-a] pyrazin- 1 (2H)-one

(5)-7-(2-Chloro-5-methylpyridin-4-yl)-2-((l,3-dimethyl-lH-l,2,4-triazol-5-yl)methyl)-3- methyl-3,4-dihydropyrrolo[l,2-a]pyrazin-l(2H)-one (Intermediate 11; 143 mg, 0.37 mmol), 1 -methyl- lH-pyrazol-5-amine (72.2 mg, 0.74 mmol), cesium carbonate (363 mg, 1.11 mmol) and [(2-di-cyclohexylphosphino-3,6-dimethoxy-2',4',6'-triisopropyl-l, - biphenyl)-2-(2'-amino-l, -biphenyl)]palladium(II) methanesulfonate (33.7 mg, 0.04 mmol) in 1,4-dioxane (5 mL) were stirred under an atmosphere of nitrogen at 110 °C for 8 hours. The solvent was then removed by distillation under vacuum. The crude product was purified by flash silica chromatography (elution gradient 3 to 6% MeOH in DCM). Product containing fractions were evaporated to dryness to afford a solid. The crude product was further purified by preparative HPLC (XSelect CSH Prep CI 8 OBD column, 5μ silica, 19 mm diameter, 150 mm length), using decreasingly polar mixtures of water (containing 0.01% NH₄HC0₃) and MeCN as eluents. Fractions containing the desired compound were evaporated to dryness to afford a (5)-2-((l,3-dimethyl-lH-l,2,4-triazol-5-yl)methyl)-3- methyl-7-(5-methyl-2-((l -methyl- lH-pyrazol-5-yl)amino)pyridin-4-yl)-3, 4- dihydropyrrolo[l,2-a]pyrazin-l(2H)-one (Example 3; 47.5 mg, 28.7%) as a solid. ^!H NMR (400 MHz, DMSO, 25.2°C) 1.18 (3H, d), 3.19 (3H, s), 2.28 (3H, s), 3.66 (3H, s), 3.79 (3H, s), 3.96 - 4.01 (IH, m), 4.10 - 4.14 (IH, dd), 4.24 - 4.28 (IH, dd), 4.39 (IH, d), 5.15 (IH, d), 6.21 (IH, d), 6.79 (IH, s), 6.94 (IH, d), 7.32 (IH, d), 7.38 (IH, d), 7.95 (IH, s), 8.50 (IH, s). m/z (ES+), [M+H]+ = 446.

Intermediate 11

(S)-7-(2-Chloro-5-methylpyridin-4-yl)-2-((l,3-dimethyl-lH-l,2,4-triazol-5-yl)methyl)- 3-methyl-3,4-dihydropyrrolo [ 1 ,2-a] pyrazin- 1 (2H)-one

NaH (43.5 mg, 1.09 mmol) was added to (5)-7-(2-chloro-5-methylpyridin-4-yl)-3-methyl- 3,4-dihydropyrrolo[l,2-a]pyrazin-l(2H)-one (Intermediate 12; 150 mg, 0.54 mmol) in DMF (3 mL) at 0°C under nitrogen. The resulting solution was stirred at 0 °C for 1 hour. 5-(chloromethyl)-l,3-dimethyl-lH-l,2,4-triazole (79 mg, 0.54 mmol) was added to the reaction mixture at 0°C. The resulting solution was stirred at 20 °C for 12 hours. The reaction mixture was quenched with water (15 mL), extracted with EtOAc (3 x 20 mL), dried over Na₂S04, filtered and evaporated to afford an oil. The crude product was purified by flash silica chromatography (elution gradient 3 to 6% MeOH in DCM). Pure fractions were evaporated to dryness to afford (5)-7-(2-chloro-5-methylpyridin-4-yl)-2-((l,3- dimethyl- lH-l,2,4-triazol-5-yl)methyl)-3-methyl-3,4-dihydropyrrolo[l,2-a]pyrazin-l(2H)- one (Intermediate 11; 143 mg, 68.3%) as an oil. ^!H (400 MHz, CDCb, 23.9 °C) 1.34 (3H, d), 2.40 (3H, s), 2.42 (3H, d), 3.98 (4H, s), 4.29 (2H, d), 4.35 (IH, dd), 5.42 (IH, d), 7.01 (IH, d), 7.18 (IH, d), 7.32 (IH, s), 8.22 (IH, s). m/z (ES+), [M+H]+ = 385. Intermediate 12

(S)-7-(2-Chloro-5-methylpyridin-4-yl)-3-methyl-3,4-dihydropyrrolo[l,2-a]pyrazin- l(2H)-one

A mixture of (S)-methyl l -(2-aminopropyl)-4-(2-chloro-5-methylpyridin-4-yl)-lH-pyrrole- 2-carboxylate (Intermediate 13; 4.17 g, 13.55 mmol) and 7N ammonia in MeOH (232 ml, 1625.86 mmol) was stirred at room temperature overnight. The solvent was removed under reduced pressure to afford a solid. The solid was dissolved in DCM and purified by silica chromatography (elution gradient 0-5% MeOH in DCM). Fractions containing desired product were combined and the solvent removed under reduced pressure to afford (S)-7-(2-chloro-5 -methylpyridin-4-yl)-3 -methyl-3 ,4-dihydropyrrolo [ 1 ,2-a]pyrazin- 1 (2H)- one (Intermediate 12; 2.72 g, 72.8%) as a solid. ^!H NMR (400 MHz, DMSO, 30 °C) 1.21 (3H, d), 2.40 (3H, s), 3.73 - 3.87 (1H, m), 3.86 - 3.93 (1H, m), 4.25 (1H, dd), 7.09 (1H, d), 7.46 - 7.58 (2H, m), 7.82 (1H, s), 8.21 (1H, s). m/z (ES+), [M+H]+ = 276.

Intermediate 13

(S)-Methyl 1 -(2-aminopropyl)-4-(2-chloro-5-methylpyridin-4-yl)- lH-pyrrole-2- carbox late

Trifluoroacetic acid (10.38 mL, 135.58 mmol) was added to (5)-methyl l-(2-((tert- butoxycarbonyl)amino)propyl)-4-(2-chloro-5-methylpyridin-4-yl)-lH-pyrrole-2- carboxylate (Intermediate 4; 5.53 g, 13.56 mmol) in DCM (100 mL) at room temperature. The resulting solution was stirred at room temperature for 2 hours and the solvent removed under reduced pressure. The residue was dissolved in MeOH loaded onto an SCX-2 column and washed with MeOH. The product was eluted with 7N ammonia in MeOH to afford (iS)-methyl 1 -(2-aminopropyl)-4-(2-chloro-5-methylpyridin-4-yl)- lH-pyrrole-2- carboxylate (Intermediate 13; 4.17 g, 100 %) as a gum. m/z (ES+), [M+H]+ = 308.

Example 4

(S)-3-Methyl-7-(5-methyl-2-((l-methyl-lH-pyrazol-5-yl)amino)pyridin-4-yl)-2-((2- methyl-2H- 1 ,2,3-triazol-4-yl)methyl)-3,4-dihydropyrrolo [ 1 ,2-a] pyrazin- 1 (2H)-one

(5)-7-(2-chloro-5-methylpyridin-4-yl)-3-methyl-2-((2-methyl-2H-l,2,3-triazol-4- yl)methyl)-3,4-dihydropyrrolo[l,2-a]pyrazin-l(2H)-one (Intermediate 14; 231mg, 0.62 mmol), 1 -methyl- lH-pyrazol-5-amine (121 mg, 1.25 mmol), cesium carbonate (609 mg, 1.87 mmol) and [(2-di-cyclohexylphosphino-3,6-dimethoxy-2',4',6'-triisopropyl-l, - biphenyl)-2-(2'-amino-l, -biphenyl)]palladium(II) methanesulfonate (56.5 mg, 0.06 mmol) in 1,4-dioxane (5 mL) were stirred under an atmosphere of nitrogen at 110 °C for 8 hours. The solvent was removed by distillation under vacuum. The residue was purified by flash silica chromatography (elution gradient 3 to 6% MeOH in DCM). Pure fractions were evaporated to dryness to afford a solid. The solid was further purified by preparative HPLC (XSelect CSH Prep C18 OBD column, 5μ silica, 19 mm diameter, 150 mm length), using decreasingly polar mixtures of water (containing 0.01% NH4HCO3) and MeCN as eluents. Fractions containing the desired compound were evaporated to dryness to afford (5)-3-methyl-7-(5-methyl-2-((l-methyl-lH-pyrazol-5-yl)amino)pyridin-4-yl)-2-((2-methyl- 2H-l,2,3-triazol-4-yl)methyl)-3,4-dihydropyrrolo[l,2-a]pyrazin-l(2H)-one (Example 4; 76 mg, 28.1 %) as a solid. ^!H NMR (400 MHz, DMSO, 25.1 °C) 1.15 (3H, d), 2.28 (3H, s), 3.66 (3H, s), 3.92 - 3.96 (IH, m), 4.12 (4H, m), 4.23 - 4.28 (IH, dd), 4.32 (IH, d), 5.10 (IH, d), 6.21 (IH, d), 6.80 (IH, s), 6.93 (IH, d), 7.31 (IH, d), 7.34 (IH, d), 7.69 (IH, s), 7.95 (IH, s), 8.50 (IH, s). m/z (ES+), [M+H]+ = 432. Intermediate 14

(S)-7-(2-Chloro-5-methylpyridin-4-yl)-3-methyl-2-((2-methyl-2H-l,2,3-triazol-4- yl)methyl)-3,4-dihydropyrrolo[l,2-a]pyrazin-l(2H)-one

NaH (43.5 mg, 1.09 mmol) was added to (5)-7-(2-chloro-5-methylpyridin-4-yl)-3-methyl- 3,4-dihydropyrrolo[l,2-a]pyrazin-l(2H)-one (Intermediate 12; 150 mg, 0.54 mmol) in DMF (3 mL) at 0°C under nitrogen. The resulting solution was stirred at 0°C for 1 hour. 4-(bromomethyl)-2-methyl-2H-l,2,3-triazole (Intermediate 14a; 96 mg, 0.54 mmol) was added to the reaction mixture at 0°C and the resulting solution stirred at 20 °C for 12 hours. The reaction mixture was quenched with water (15 mL), extracted with EtOAc (4 x 15 mL), dried over Na₂S04, filtered and evaporated to afford an oil. The crude product was purified by flash silica chromatography (elution gradient 3 to 6% MeOH in DCM). Pure fractions were evaporated to dryness to afford (5)-7-(2-chloro-5-methylpyridin-4-yl)-3- methyl-2-((2-methyl-2H-l,2,3-triazol-4-yl)methyl)-3,4-dihydropyrrolo[l,2-a]pyrazin- l(2H)-one (Intermediate 14; 231 mg, 115 %) as an oil. ^lH (400 MHz, CDCb, 23.9°C) 1.33 (3H, d), 2.48 (3H, s), 3.91 - 4.06 (2H, m), 4.20 (3H, s), 4.23 - 4.35 (2H, m), 5.30 - 5.39 (1H, m), 7.08 (1H, d), 7.24 (1H, d), 7.44 (1H, s), 7.62 (1H, s), 8.28 (1H, s). m/z (ES+), [M+H]+ = 371.

Intermediate 14a is commercially available but can be synthesised on multi-grams scale by the method described below:

Intermediate 14a

4-(Bromomethyl)-2-methyl-triazole

To a solution of (2-methyltriazol-4-yl)methanol (Intermediate 14b; 50.00 g, 442.01 mmol) in MTBE (600.00 mL) was added dropwise PBr₃ (119.65 g, 442.01 mmol,) and the mixture was stirred at 25 °C for 16 hours under nitrogen atmosphere. The mixture was quenched with water (400 mL) and extracted with MTBE (600 mL x 3). The organic layer was concentrated under vacuum to give the crude product as oil. The crude product was purified by column chromatagraphy eluting with petrol ether:EtOAc 50: 1 to 30: 1 to give 4- (bromomethyl)-2-methyl-triazole (Intermediate 14a; 55.00 g, 70.70% yield) as an oil. TLC petroleum ether: EtOAc = 20: 1, R_f= 0.4. ^lH NMR: (CDC1 , 400 MHz) δ 7.58 (s,lH), 4.51 (s, 2H), 4.18 (s, 3H).

Intermediate 14b

(2-Meth ltriazol-4-yl)methanol

Batch 1 : To a solution of (5-bromo-2-methyl-triazol-4-yl)methanol (Intermediate 14c; 60.00 g, 312.48 mmol) in MeOH (1.20 L), Pd/C (312.48 mmol), HCOOH (15.01 g, 312.48 mmol) and NMM (31.61 g, 312.48 mmol) was added and the mixture was stirred at 40 °C under H₂ (45 psi) for 16 hours. Batch 2: To a solution of (5 -bromo-2 -methyl -triazol-4- yl)methanol (Intermediate 14c; 60.00 g, 312.48 mmol) in MeOH (1.20 L), Pd/C (312.48 mmol), HCOOH (15.01 g, 312.48 mmol) and NMM (31.61 g, 312.48 mmol) was added and the mixture was stirred at 40 °C under H₂ (45 psi) for 16 hours. Batches 1 and 2 above were combined and the reaction mixture was filtered through a pad of celite, and the filtrate was concentrated under vacuum to give (2-methyltriazol-4-yl)methanol

(Intermediate 14b; 64 g, 565.77 mmol, 90.53%>) as an oil which was used without further purification. 'H NMR (CDC1 , 400 MHZ) δ 7.54 (s,lH), 4.74 (s, 2H), 4.16 (s, 3H), 3.70 (br s, 1H).

Intermediate 14c

(5-Bromo-2-methyl-triazol-4-yl)methanol

To a solution of 5-bromo-2-methyl-2H-l,2,3-triazole-4-carboxylic acid (Intermediate 14d; 100 g, 485.44 mmol) in THF (1.5 L) was added dropwise BH3.THF (83.44 g, 970.88 mmol) at 25 °C under nitrogen atmosphere. The mixture was stirred at 25 °C for 16 hours. The mixture was quenched with of H₂0 (1 L) and stirred at 25 °C for 1 hour. The aqueous phased was then extracted with MTBE (3 L x 3), the organics were dried with Na₂S04 and concentrated under vacuum to give (5-bromo-2-methyl-triazol-4-yl) methanol

(Intermediate 14c; 75.00 g, 80.46% yield) as an oil. ^!H NMR (CDCI3, 400 MHz) δ 4.70 (s, 2H), 4.17(s, 3H), 2.20 (br s, 1H). m/z (ES+) [M+H]+ 192/194. Intermediate 14d

5-Bromo-2-methyl-2H- 1 ,2,3-triazole-4-carboxylic acid

A solution of 4,5-dibromo-2-methyl-2H-l,2,3-triazole (Intermediate 14e; 144 g, 597.81 mmol) in anhydrous THF (1.5 L) was cooled to -30 °C under nitrogen atmosphere and i- PrMgCl (330 mL, 658 mmol, 2M in THF) was added dropwise. The solution was stirred at -30 °C for 1 hour, and then bubbled with C0₂ for 3 hours at <10 °C. The reaction was then stirred at 25 °C for 16 hours. The mixture was quenched with aqueous HC1 (-3000 mL, 0.1M) to pH = ~2 and extracted with EtOAc (3 L x 3). The organic phase was then extracted with aqueous NaOH (0.1M, 2 L x 3). The aqueous phase was then added to aqueous HC1 (~6 L, 0.1M) to pH=~2 and extracted with EtOAc (3L x 3). The organic phase was dried with Na₂S0₄ and concentrated under vacuum to give 5-bromo-2-methyl- 2H-l,2,3-triazole-4-carboxylic acid (Intermediate 14d; 105 g, 85.26% yield) as a white solid. ^lH NMR (DMSO, 400 MHz) δ 4.23 (s, 3H). ¹³C-NMR (400MHz, DMSO) δ 160.86, 138.23, 124.52, 43.38.

Intermediate 14e

4,5-Dibromo-2-methyl-2H-l,2,3-triazole

Batch 1 : To a solution of 4,5-dibromo-lH-triazole (Intermediate 14f; 490.00 g, 2.16 mol) in DMF (3.2 L) was added potassium carbonate (358.23 g, 2.59 mol). The mixture was cooled to -10°C under a nitrogen atmosphere and iodomethane (147.91 mL, 2.38 mol) was added dropwise. The reaction was then stirred at 25°C for 16 hours. Batch 2: To a solution of 4,5-dibromo-lH-triazole (Intermediate 14f; 400 g, 1.76 mol, 1.00 eq) in DMF (2.8 L) was added potassium carbonate (291.9 g, 2.11 mol). The mixture was cooled to - 10°C under a nitrogen atmosphere and iodomethane (131.48 mL, 2.11 mol) was added dropwise. The reaction was then stirred at 25°C for 16 hours. Batches 1 and 2 were then combined and the reaction was quenched by the addition of water (4.2 L) and the aqueous phase extracted with MTBE (7 L x 3). The organic extract was concentrated under vacuum to approximately 700 mL and isopropanol (2 L) was added dropwise. This mixture was then stirred at 25 °C for 2 hours and the resulting precipitate filtered and dried under vacuum to afford undesired 4,5-dibromo-l-methyltriazole (220 g, 23.5%) as a solid which showed the following NMR spectral data: ^!H NMR (400MHz, CDCb) δ 4.09 (s, 3H). ¹³CNMR (400MHz, CDCb) δ 123.03, 113.09, 37.00. The filtrate was concentrated under vacuum to afford an oil, isopropanol (1 L) was added and resulting solution was warmed to 50 °C and then water (3 L) was added dropwise. The mixture was cooled to 25°C and stirred for 5 hours and the resulting precipitate was collected by filtration, washed with water (300 mL x 2) and, dried under vacuum at 50°C for 16 hours to afford 4,5-dibromo-2- methyl-2H-l,2,3-triazole (Intermediate 14e; 570 g, 60.8% yield) as a solid. ^!H NMR (400MHz, CDCb) δ 4.18 (s, 3H). ¹³C NMR (400MHz, CDCb) δ 124.25, 43.07.

Intermediate 14f

4,5-Dibromo-lH-triazole

Br₂ (930 g, 5.82 mol) was added dropwise to a stirred solution of lH-triazole (300.00 g, 4.34 mol, 252.10 mL) in H₂0 (2 L) at 40 to 45 °C. The resulting solution was stirred for a further 1 hour. The precipitate was filtered off and further Br₂ (617.28 g, 3.86 mol) was added to the filtrate, then it was kept at 25 °C for 16 hours. A second precipitate was filtered off. The combined filtered off solids were washed with water (1 L x 3), dried under vacuum and re-crystallized from MeOH (-400 mL) to give 4,5-dibromo-lH-triazole (Intermediate 14f; 890 g, 90.39% yield) as an off-white solid, m/z (ES+) [M+H]+

226/228/230.

Example 5

(S)-3-Methyl-2-((l-methyl-lH-l,2,3-triazol-5-yl)methyl)-7-(5-methyl-2-((l-methyl-lH- razol-5-yl)amino)pyridin-4-yl)-3,4-dihydropyrrolo [ 1 ,2-a] py razin-1 (2H)-one

(5)-7-(2-chloro-5-methylpyridin-4-yl)-3-methyl-2-((l-methyl-lH-l,2,3-triazol-5- yl)methyl)-3,4-dihydropyrrolo[l,2-a]pyrazin-l(2H)-one (Intermediate 15; 173 mg, 0.47 mmol), 1 -methyl- lH-pyrazol-5-amine (91 mg, 0.93 mmol), cesium carbonate (304 mg,

0.93 mmol) and chloro[(4,5-bis(diphenylphosphino)-9,9-dimethylxanthene)-2-(2'-amino-

1, -biphenyl)]palladium(II) (41.5 mg, 0.05 mmol) in 1,4-dioxane (5 mL) were stirred under an atmosphere of nitrogen at 120°C for 8 hours. The solvent was removed by distillation under vacuum. The crude product was purified by flash silica chromatography (elution gradient 4 to 5% MeOH in DCM). Pure fractions were evaporated to dryness to afford a solid. The crude product was purified by preparative HPLC (XSelect CSH Prep C18 OBD column, 5μ silica, 19 mm diameter, 150 mm length), using decreasingly polar mixtures of water (containing 0.01% NH4HCO3) and MeCN as eluents. Fractions containing the desired compound were evaporated to dryness to afford (S)-3-methyl-2-((l- methyl- IH- 1 ,2, 3-triazol-5-yl)methyl)-7-(5-methyl-2-((l -methyl- lH-pyrazol-5- yl)amino)pyridin-4-yl)-3,4-dihydropyrrolo[l,2-a]pyrazin-l(2H)-one (Example 5; 35.0 mg, 17.4%) as a solid. 'H NMR (400 MHz, CDCb, 25.5 °C) 1.30 (3H, d), 2.41 (3H, s), 3.83 - 3.86 (4H, m), 3.92 - 4.01 (IH, m), 4.11 (3H, s), 4.22 (IH, dd), 4.29 (IH, d), 5.48 (IH, d), 6.20 (IH, d), 6.73 (IH, s), 7.00 (IH, d), 7.17 (IH, d), 7.54 (IH, d), 7.71 (IH, s), 7.87 (IH, s), 8.73 (IH, s). m/z (ES+), [M+H]+ = 432. Intermediate 15

(S)-7-(2-Chloro-5-methylpyridin-4-yl)-3-methyl-2-((l-methyl-lH-l,2,3-triazol-5- l)methyl)-3,4-dihydropyrrolo[l,2-a]pyrazin-l(2H)-one

NaH (65.3 mg, 1.63 mmol) was added to (5)-7-(2-chloro-5-methylpyridin-4-yl)-3-methyl- 3,4-dihydropyrrolo[l ,2-a]pyrazin-l(2H)-one (Intermediate 12; 150 mg, 0.54 mmol) in DMF (3 mL) at 25°C under nitrogen. The resulting solution was stirred at 25°C for 30 minutes. 5-(chloromethyl)-l-methyl-lH-l ,2,3-triazole hydrochloride (183 mg, 1.09 mmol) was added to reaction mixture and the resulting solution was stirred at 25°C for 12 hours. The reaction mixture was poured into water (15 mL), extracted with EtOAc (3 x 10 mL), dried over Na₂S04, filtered and evaporated to afford an oil. The crude product was purified by flash silica chromatography (elution gradient 0 to 5% MeOH in DCM). Pure fractions were evaporated to dryness to afford (5)-7-(2-chloro-5-methylpyridin-4-yl)-3-methyl-2- (( 1 -methyl- IH- 1 ,2,3-triazol-5-yl)methyl)-3 ,4-dihydropyrrolo[ 1 ,2-a]pyrazin- 1 (2H)-one (Intermediate 15; 173 mg, 86%) as a foam. ^!H NMR (400 MHz, CDCb , 25.0°C) 1.31 (3H, d), 2.44 (3H, s), 3.77 - 3.84 (IH, m), 3.97 (IH, dd), 4.13 (3H, s), 4.19 - 4.33 (2H, m), 5.51 (IH, d), 7.03 (IH, d), 7.23 (IH, d), 7.35 (IH, s), 7.72 (IH, s), 8.24 (IH, s). m/z (ES+), [M+H]+ = 371.

Example 6

(S)-3-Methyl-2-((l-methyl-lH-l,2,3-triazol-4-yl)methyl)-7-(5-methyl-2-((l-methyl-lH- pyrazol-5-yl)amino)pyridin-4-yl)-3,4-dihydropyrrolo [ 1 ,2-a] py razin-1 (2H)-one

(5)-7-(2-Chloro-5-methylpyridin-4-yl)-3-methyl-2 (l-methyl H ,2,3-triazol-4- yl)methyl)-3,4-dihydropyrrolo[l,2-a]pyrazin-l(2H)-one (Intermediate 16; 126 mg, 0.34 mmol), 1 -methyl- lH-pyrazol-5-amine (66.0 mg, 0.68 mmol), cesium carbonate (332 mg, 1.02 mmol) and [(2-di-cyclohexylphosphino-3,6-dimethoxy-2',4',6'- triisopropyl-Ι, - biphenyl)-2-(2'-amino-l,r -biphenyl)]palladium(II) methanesulfonate (30.8 mg, 0.03 mmol) in 1,4-dioxane (3 mL) were stirred under an atmosphere of nitrogen at 120 °C for 8 hours. The solvent was removed by distillation under vacuum. The crude product was purified by flash silica chromatography (elution gradient 3 to 5% MeOH in DCM). Pure fractions were evaporated to dryness to afford a oil. The crude product was purified by preparative HPLC (XSelect CSH Prep C18 OBD column, 5μ silica, 19 mm diameter, 150 mm length), using decreasingly polar mixtures of water (containing 0.01% NH4HCO3) and MeCN as eluents. Fractions containing the desired compound were evaporated to dryness to afford (5)-3-methyl-2-((l-methyl-lH-l,2,3-triazol-4-yl)methyl)-7-(5-methyl-2-((l- methyl-lH-pyrazol-5-yl)amino)pyridin-4-yl)-3,4-dihydropyrrolo[l,2-a]pyrazin-l(2H)-one (Example 6; 46.2 mg, 31.5%) as a solid. ¾ NMR (400 MHz, CDCI3, 20.FC) 1.35 (3H, d), 2.36 (3H, s), 3.79 (3H, s), 3.86 - 3.96 (IH, m), 4.09 (3H, s), 4.14 - 4.30 (2H, m), 4.42 (IH, d), 5.15 (IH, d), 6.16 (IH, d), 6.54 (IH, s), 6.62 (IH, s), 6.89 (IH, d), 7.08 (IH, d), 7.52 (IH, d), 7.68 (IH, s), 7.99 (IH, s). m/z (ES+), [M+H]+ = 432.

Intermediate 16

(S)-7-(2-Chloro-5-methylpyridin-4-yl)-3-methyl-2-((l-methyl-lH-l,2,3-triazol-4- yl)methyl)-3,4-dihydropyrrolo[l,2-a]pyrazin-l(2H)-one

\

NaH (72.5 mg, 1.81 mmol) was added to (5)-7-(2-chloro-5-methylpyridin-4-yl)-3-methyl- 3,4-dihydropyrrolo[l,2-a]pyrazin-l(2H)-one (Intermediate 12; 100 mg, 0.36 mmol) in DMF (2.5 mL) at 25°C under nitrogen. The resulting solution was stirred at 25 °C for 30 minutes. 4-(chloromethyl)-l-methyl-lH-l,2,3-triazole hydrochloride (183 mg, 1.09 mmol) was added and the resulting solution was stirred at 25 °C for 12 hours. The reaction mixture was poured into water (15 mL), extracted with EtOAc (3 x 10 mL), dried over Na₂S04, filtered and evaporated to afford an oil. The crude product was purified by flash silica chromatography (elution gradient 0 to 5% MeOH in DCM). Pure fractions were evaporated to dryness to afford (5)-7-(2-chloro-5-methylpyridin-4-yl)-3-methyl-2-((l- methyl- IH- 1 ,2,3-triazol-4-yl)methyl)-3 ,4-dihydropyrrolo[ 1 ,2-a]pyrazin- 1 (2H)-one

(Intermediate 16; 126 mg, 94 %) as an oil. ^lH NMR (400 MHz, CDCb, 22.6°C) 1.37 (3H, d), 2.43 (3H, s), 3.94 (IH, d), 4.10 (3H, s), 4.21 - 4.34 (2H, m), 4.43 (IH, d), 5.18 (IH, d), 7.00 (IH, d), 7.17 (IH, d), 7.35 (IH, s), 7.70 (IH, s), 8.23 (IH, s). m/z (ES+), [M+H]+ = 371.

Claims

73 CLAIMS

1. A compound of the Formula (I) or a pharmaceutically-acceptable salt thereof

(I)

wherein:

R¹ is triazolyl, optionally substituted on one ring carbon atom by methyl provided that no more than 1 ring carbon atom is substituted; and, optionally substituted on one ring nitrogen by methyl provided that no more than 1 ring nitrogen atom is substituted.

2. A compound of formula (I) or a pharmaceutically-acceptable salt thereof, as claimed in claim 1, wherein:

3. A compound as claimed in claims 1 to 2, or a pharmaceutically-acceptable salt thereof, wherein R¹ is selected from 6-methylpyrimidin-4-yl, 2-methylpyrimidin-4-yl, 1,3- dimethyl-l,2,4-triazol-5-yl, l-methyl-l,2,3-triazol-5-yl, 2-methyl-l,2,3-triazol-4-yl and 1- methyl- 1 ,2,3-triazol-4-yl. 74

4. A compound as claimed in claims 1 to 3, or a pharmaceutically-acceptable salt thereof, wherein R¹ is 2-methylpyrimidin-4-yl.

5. A compound as claimed in claims 1 to 3, or a pharmaceutically-acceptable salt thereof, wherein R¹ is 2-methyl-l,2,3-triazol-4-yl.

6. A compound as claimed in claim 1, or a pharmaceutically-acceptable salt thereof, wherein said compound is any one of Examples 1 to 6.

7. A compound as claimed in claim 1, or a pharmaceutically-acceptable salt thereof, wherein said compound is any one of Examples 2 and 4.

8. A compound as claimed in any of the preceding claims, or a pharmaceutically- acceptable salt thereof for use as a medicament.

9. A compound as claimed in any of claims 1 to 7, or a pharmaceutically-acceptable salt thereof for use in the prevention or treatment of cancer in a warm-blooded animal such as man.

10. A compound of the Formula (I), or a pharmaceutically-acceptable salt thereof, as claimed in any of claims 1 to 7 for use in the treatment of NSCLC, pancreatic or colorectal cancers.

11. A method for the prevention or treatment of cancer in a warm-blooded animal, such as man, in need of such treatment which comprises administering to said animal an effective amount of a compound of the Formula (I) as claimed in any of claims 1 to 7, or a pharmaceutically-acceptable salt thereof.

12. A pharmaceutical composition comprising a compound of Formula (I) or a pharmaceutically-acceptable salt thereof, as claimed in any of claims 1 to 7, and a pharmaceutically-acceptable diluent or carrier. 75

13. A combination suitable for use in the treatment of cancer comprising a compound of Formula (I) as claimed in any of claims 1 to 7, or a pharmaceutically-acceptable salt thereof and another anti-tumour agent.

14. A combination as claimed in claim 13 comprising a compound of Formula (I) as claimed in any of claims 1 to 7 or a pharmaceutically-acceptable salt thereof and a MEK inhibitor, such as selumetinib (ARRY-142886).

15. A process for preparing a compound of formula (IV), said process comprising: a) reaction of a compound of formula (V) with a compound of formula (X) in the presence of a suitable base in a suitable solvent, under conditions of ambient or elevated temperatures;

(IV)

(V)

wherein;

R² is an alkyl group;

L¹ is a leaving group;

P² is a protecting group; and