Lunresertib Drug Asset Due Diligence Report 2026

This Lunresertib Drug Asset Due Diligence Report was built with PatSnap Life Sciences MCP workflows. Drug & Asset MCP establishes identity, ownership and stage; Clinical Trials MCP checks design, endpoints and readouts; Company & Deal Intelligence MCP reconstructs transaction precedent. Explore the MCP servers used in this report.

Decision date: 16 September 2026. Currency fields are presented in US$ millions as returned by the deal dataset. This is a screening memorandum, not legal, medical, patent or investment advice.

Phase 2

Highest phase

Registered trials

Result records

Matched deals

Executive recommendation: CONDITIONAL GO

Decision memo

Advance with milestone-based economics while efficacy durability, safety differentiation, patent scope, and market positioning are validated.

The central underwriting question is whether Lunresertib can convert its Small molecule drug profile and CCNE1 x PKMYT1 biology into clinically meaningful differentiation while preserving an investable safety, IP and commercial position.

1. Asset identity and development status

Asset	Lunresertib (query alias: Lunresertib)
Modality / target	Small molecule drug; CCNE1 x PKMYT1; CCNE1 inhibitors, PKMYT1 inhibitors
Highest global status	Phase 2
Originator	Repare Therapeutics, Inc.
Active developers	Canadian Cancer Trials Group, University of Pennsylvania, Repare Therapeutics, Inc.

The MCP disease footprint includes ER-positive/HER2-negative Breast Cancer, Colorectal Cancer, Endometrial Carcinoma. The highest-phase flag is a useful orientation point, but the licensing case depends on indication-level evidence and rights, not the global label alone.

2. Clinical program: design and endpoint audit

Registry	Phase	Status	Enrollment	Lead primary endpoint
NCT06107868	Phase 1	Active, not recruiting	6	Primary endpoint not disclosed in English source
NCT05605509	Phase 2	Completed	28	Primary endpoint not disclosed in English source
NCT05601440	Phase 2	Recruiting	484	Primary endpoint not disclosed in English source

The trial set should be diligenced for randomization, comparator relevance, endpoint hierarchy, analysis population, multiplicity, geographic mix and readout timing. For early-stage studies, safety and dose selection can be as decision-critical as response rate.

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3. Clinical readouts: what is known

First data disclosure of the Phase I trial of the first in class combination of WEE1 inhibitor zedoresertib with PKMYT1 inhibitor lunresertib in patients with advanced solid tumors harboring CCNE1, FBXW7, or PPP2R1A genomic alterations

Phase 1; n=54; evaluation: Positive. Reported fields: DLT = 4.0 Pts

Phase 1 Study of the PKMYT1 Inhibitor RP-6306 in Combination With FOLFIRI for the Treatment of Advanced Solid Tumors

Phase 1; n=38; evaluation: Not stated in English source. Reported fields: Safety and Tolerability of RP 6306 in Combination With FOLFIRI = 1 Pts ; Safety and Tolerability of RP 6306 in Combination With FOLFIRI = 1 Pts

Efficacy and safety of the combination PKMYT1-inhibitor lunresertib and ATR-inhibitor camonsertib in patients with ovarian and endometrial cancers: Phase I MYTHIC study (NCT04855656)

Phase 1; n=67; evaluation: Positive. Reported fields: Adverse Event: Gr3 TRAE anemia = 26.9% ; Adverse Event: Gr3 TRAE anemia = 26.9%

These fields are structured evidence signals, not a substitute for statistical review. The next diligence pass should reconcile denominators, confidence intervals, follow-up, censoring, dose cohorts and treatment-emergent toxicity against the original abstract, registry and protocol.

4. Market and competitive position

Lunresertib addresses ER-positive/HER2-negative Breast Cancer, Colorectal Cancer, Endometrial Carcinoma. Commercial attractiveness rests on addressable patients, treatment-line placement, duration, administration burden, pricing and displacement of entrenched standards. The modality—Small molecule drug—must demonstrate a benefit large enough to offset class-specific safety and operational costs.

The MCP screen returned 2 matched transaction record(s) under the scope “asset-specific.” Partner activity is a market-validation signal, but it does not establish net present value.

5. Transaction precedent and economics

Date	Transaction	Phase at deal	Disclosed economics
2025-07-15	Repare Therapeutics Enters Exclusive Worldwide Licensing Agreement with Debiopharm for Lunresertib	Phase 2	US$10.0M upfront; US$257.0M milestones
2024-01-04	Repare Therapeutics and Debiopharm Partner to Explore the Synthetic Lethal Combination of PKMYT1 and WEE1 Inhibition in Cancer	Phase 1	Financial terms not disclosed

Headline values are not directly comparable. Diligence should normalize upfront cash, equity, development and sales milestones, tiered royalties, opt-in mechanics, cost sharing, change-of-control clauses and geography.

6. IP and freedom-to-operate screen

The milestone feed surfaced a patent-application signal described as “Ras inhibitors in combination therapy for use in treating cancers”. The milestone feed surfaced a patent-application signal described as “Crystalline forms, crystalline salt forms, compositions containing the same, and methods of using the same”. The milestone feed surfaced a patent-application signal described as “Combination therapies including MYT1 inhibitors and wee1 inhibitors”.

The claim chart should separately test composition or sequence coverage, formulation and dosing, indication and biomarker claims, combinations, manufacturing know-how, prosecution history, term extensions and third-party blocking rights.

7. Principal risks and diligence gates

Therapeutic index and off-target toxicity
Resistance biology and biomarker-defined patient selection
Differentiation from established and emerging standards

Cross-functional diligence should also test CMC comparability, supply chain, pharmacovigilance, regulatory correspondence, data integrity, investigator concentration, partner obligations and change-of-control restrictions.

8. Final go/no-go memorandum

CONDITIONAL GO