Targeting MAT2A in CDKN2A/MTAP-deleted Cancers

American Association for Cancer Research 2019 Annual ConferenceSymposium on Exploiting Metabolic Vulnerabilities of CancerApril 1st 2019

Targeting MAT2A in Cancers with Deletion of CDKN2A/MTAP

Marjon et al. Cell Reports 2016

CDKN2A/MTAP Deleted Cancer Cell

AG-270

MTAP deletion frequency

MTAP wt

MTAP null

Growth Inhibition in Cancer Cells HCT116 +/- MTAP MTAP-deleted HCT116 Xenograft Model

MTAP-WT HCT116 Xenograft Model

MAT2Ai

MAT2Ai

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m3 )

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Agios MAT2A Inhibitors Selectively Impact Proliferation of MTAP-null Cancers

Esophageal (SCC) Model

NSCLC (SCC) Model

MAT2A Inhibitor AG-270 Possesses Broad Activity in ‘Mouse Clinical Trial’ Using Patient Derived Xenograft Models

Anti-tumor activity observed in a variety of models, with examples of regressions / tumor stasis

Efficacy in ~70 MTAP-deleted PDX models

N=3 per model; established tumors treated at 200 mpk AG-270 QD

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Esophageal (SCC) PDX Model

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MTAP-deletion Enriches for AG-270 Sensitivity in NSCLC PDX Models

MTAP-selective Tumor Growth InhibitionIn NSCLC PDX

(Unpaired t test p=0.02)

NSCLC PDX models validate MTAP-deletion as a biomarker

• MTAP-deleted and MTAP wt tumors have similar drug exposure

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MTAP-deletion Enriches for AG-270 Sensitivity in NSCLC PDX Models

MTAP-selective Tumor Growth InhibitionIn NSCLC PDX

(Unpaired t test p=0.02)

NSCLC PDX models validate MTAP-deletion as a biomarker

• MTAP-deleted and MTAP wt tumors have similar drug exposure and similar reductions in Tumor SAM

Max

imal

% T

umor

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row

th In

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MTAP-deletion Enriches for AG-270 Sensitivity in NSCLC PDX Models

MTAP-selective Tumor Growth InhibitionIn NSCLC PDX

(Unpaired t test p=0.02)

Max

imal

% T

umor

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th In

hibi

tion

• MTAP-deleted and MTAP wt tumors have similar drug exposure and similar reductions in Tumor SAM but PRMT5 methyl marks only decrease in MTAP-deleted tumors

NSCLC PDX models validate MTAP-deletion as a biomarker…and provide evidence supporting the MTAPPRMT5/MAT2A mechanism

Methylation Proteomics Corroborates Role for PRMT5 as a Key Downstream Mediator of MAT2A Inhibition in MTAP-deleted Cells

HCT116 MTAP-/- and HCT116 MTAP wt cells

3-day treatmentwith MAT2Ai or DMSO

IP with PTM-specific antibodies Mono-Methyl-Arginine Asymmetrical di-methyl Arginine Symmetrical di-methyl Arginine Pan-methyl Lysine

LC-MS/MS

336

# PRMT5 SDMA peptides reduced >4-fold upon MAT2Ai treatment:

HCT116 MTAP-/-

HCT116 MTAP+/+

RNA Processing

MAT2A Inhibition Selectively Disrupts Splicing in MTAP-deleted Cells

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• MAT2A Inhibition leads to substantial dysregulation of splicing, including large increase in transcripts containing Detained Introns (DIs)

• DI-containing transcripts fail to export into the cytosol and thus are not translated (Boutz et al G&D 2015)

• MAT2A Inhibitor treatment DIs include critical genes in DNA damage repair and cell cycle

AG-270 Treatment Induces Substantial Mitotic Defects in HCT116 MTAP-/- cells

• Single Agent AG-270 treatment leads to DNA damage (γH2AX) and micronuclei formation• Effects are selectively observed in MTAP-/- cells and not in MTAP-wt cells

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In Parallel, a Large-scale Synergy Screen in >30 Cell Lines Revealed Synergy between AG-270 and Antimitotics

Pacl

itaxe

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Large Scale Synergy Screen:

20 candidate combo partnersX

36 MTAP-null cell lines

• Full dose curve matrices• Cell lines included (n):Lung (17), Esophageal & Gastric (8), Pancreatic (7), Colorectal (3), Kidney (1)

Combination Partners(ranked by extent of synergy)

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AG-270 Synergizes with AuroraB Kinase Inhibitors and Other Anti-mitotic Agents in vitro

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• AG-270 synergizes with AuroraB Kinase Inhibitors and taxanes in vitro• Synergy is selectively observed in MTAP-/- cells and not in MTAP-wt cells

Doce

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HCT116 MTAP+/+

HCT116 MTAP-/-

KP4(MTAP-deleted)

AG-270

AG-270 Synergizes with Docetaxel in MTAP-null KP4 Pancreatic Ductal Adenocarcinoma Xenograft Model

AG-270 + docetaxel combination in KP4 • Single agent and combination treatments

were well-tolerated (<5% BWL)• AG-270 + docetaxel combo is synergistic

Additional AG-270 + taxane combo studies• AG-270 + taxane combinations tested in a

variety of PDX models • Combination benefit seen in tumors of

multiple indications, including lung, pancreatic, esophageal

• Combination benefit seen with both paclitaxel and docetaxel

• PK studies rule out a drug-drug PK interaction

vehicledocetaxel

AG-270

AG-270 +docetaxel

Last dose

Mechanistic Understanding of the Pathway Downstream of MAT2A

Gene ExpressionDNA ReplicationGenome Integrity

RNA splicing concurrent with transcription1.

RNA Pol

Me

Me MeMe

Splicing complex requires PRMT52.

PRMT5

SAM

Gene ExpressionDNA ReplicationGenome Integrity

MAT2A inhibition blocks splicing3.

MAT2A

Methionine

Defects in gene expression, DNA replication, genome integrity4.

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DNA repair and cell cycle defects, leading to actionable combination partners including taxanes

5.

Summary

• MAT2A inhibition selectively blocks the proliferation of MTAP-deficient cancers in vitro and in vivo

• Inhibition of MAT2A leads to MTAP-selective effects on PRMT5 methylation, leading to substantial increase in mis-spliced transcripts

• Mis-spliced transcripts include cell cycle regulators such as Aurora Kinase B; consistent with this, MAT2A inhibition leads to mitotic defects including micronuclei formation

• Mitotic defects downstream of MAT2A create a synergistic vulnerability to antimitotics including clinically-applicable taxanes which are used as standard of care in several malignancies with frequent deletion of MTAP

Acknowledgements

Agios Team