MEN-1611 Drug Asset Due Diligence Report 2026

This MEN-1611 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: 18 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 MEN-1611 can convert its Small molecule drug profile and PI3Ks biology into clinically meaningful differentiation while preserving an investable safety, IP and commercial position.

1. Asset identity and development status

Asset	MEN-1611 (query alias: MEN-1611)
Modality / target	Small molecule drug; PI3Ks; PI3K family inhibitors
Highest global status	Phase 2
Originator	Chugai Pharmaceutical Co., Ltd.
Active developers	Stemline Therapeutics, Inc., A.Menarini Industrie Farmaceutiche Riunite Srl, Menarini Von Heyden GmbH

The MCP disease footprint includes Advanced breast cancer, Metastatic breast cancer, PIK3CA mutation/HR-positive/HER2-negative Breast Cancer. 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
NCT05810870	Phase 2	Active, not recruiting	14	Primary endpoint not disclosed in English source
NCT04495621	Phase 1/2	Completed	29	Primary endpoint not disclosed in English source
NCT03767335	Phase 1	Completed	62	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

Open-label, Multicentre, Phase Ib Dose-escalation Study of MEN1611, a PI3K Inhibitor Combined With Trastuzumab With or Without Fulvestrant, in Subjects With PIK3CA Mutated HER2 Positive Locally Recurrent Unresectable (Advanced) or Metastatic (a/m) Breast Cancer Progressed to Anti-HER2 Based Therapy

Phase 1; n=62; evaluation: Not stated in English source. Reported fields: MTD of MEN1611 in Combination With Trastuzumab ± Fulvestrant = 48 milligrams (mg) ; Number of Participants With DLTs of MEN1611 in Combination With Trastuzumab ± Fulvestrant = 0 Pts

Open-label, Multicentre, Phase Ib/II Study of MEN1611, a PI3K Inhibitor, and Cetuximab in Patients With PIK3CA Mutated Metastatic Colorectal Cancer Failing Irinotecan, Oxaliplatin, 5-FU and Anti-EGFR Containing Regimens

Phase 1/2; n=29; evaluation: Not stated in English source. Reported fields: RP2D = 48 mg ; CR = 7.1 %

Abstract PD18-05: MEN1611, a PI3K inhibitor, combined with trastuzumab ± fulvestrant for HER2+/PIK3CA mutant advanced or metastatic breast cancer: updated safety and efficacy results from the ongoing phase 1b study (B-PRECISE-01)

Phase 1; n=62; evaluation: Positive. Reported fields: Adverse Event: ketoacidosis = 1 patient experienced ketoacidosis ; Adverse Event: ketoacidosis = 1 patient experienced ketoacidosis

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

MEN-1611 addresses Advanced breast cancer, Metastatic breast cancer, PIK3CA mutation/HR-positive/HER2-negative Breast Cancer. 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 1 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
2016-11-28	Menarini Subsidiary Licenses Chugai Anticancer Candidate	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 “P13k inhibitor combination therapy”. The milestone feed surfaced a patent-application signal described as “Subject-specific treatments for venetoclax-resistant acute myeloid leukemia”. The milestone feed surfaced a patent-application signal described as “Improved pharmaceutical formulations comprising PI3k 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