Haisco opens second HSK41959 trial, pairing PRMT5 drug with chemo
The Chinese oncology sponsor moves its MTAP-deletion PRMT5 inhibitor into combination testing in NSCLC and pancreatic cancer, following a still-recruiting monotherapy study.
Executive Summary
- Haisco Pharmaceutical Group has registered a new Phase 1 study pairing its PRMT5 inhibitor with standard chemotherapy in patients whose tumors carry a specific genetic deletion, extending the drug beyond the monotherapy testing already underway.
- The study is built to establish tolerability and a workable dose for the combination, not to demonstrate that the drug shrinks tumors or extends survival.
- PRMT5 inhibition in MTAP-deleted tumors is a field where several sponsors have already tried and abandoned Phase 1 programs, and only one rival compound has advanced past that stage in combination testing.
- Haisco brings a completed track record across its broader trial portfolio to a mechanism area where the company itself is not a first mover, running a parallel single-agent study of the same drug at an earlier stage.
The new trial
The study, registered under NCT07699757, will enroll an anticipated 258 patients across sites in China and has not yet begun recruiting. It targets tumors with MTAP deletion, a genetic marker linked to PRMT5 dependency, and separates patients into cohorts for non-small cell lung cancer (NSCLC) and pancreatic adenocarcinoma (PDAC). The trial's primary completion date is targeted for April 2029, with full study completion set for November 2029. NCT07699757HSK41959 With Standard Therapy in Solid Tumors With MTAP DeletionNCT07699757
What the trial measures
The registered primary endpoints are the rate and severity of adverse events and dose-limiting toxicities (DLTs), assessed over a 21-day window for NSCLC cohorts and a 28-day window for PDAC cohorts. Secondary measures include disease control rate, overall response rate, progression-free survival, and overall survival, tracked for up to approximately three years, alongside pharmacokinetic measures including drug exposure and peak concentration. This is a dose-finding and tolerability study: it is built to establish whether HSK41959 can be safely layered onto standard chemotherapy, not to prove the combination controls or shrinks tumors. NCT07699757HSK41959 With Standard Therapy in Solid Tumors With MTAP DeletionNCT07699757
A parallel program
Haisco already sponsors a separate, actively recruiting Phase 1 study of HSK41959 as a single agent in MTAP-deleted tumors, NCT06968572, with a primary completion date of March 2026. The new combination trial runs alongside that monotherapy study rather than replacing it, giving the sponsor two live vantage points, monotherapy tolerability and dosing data likely to mature first, feeding into how the combination cohorts are managed. NCT07699757HSK41959 With Standard Therapy in Solid Tumors With MTAP DeletionNCT07699757
The competitive frame
PRMT5 inhibition paired with MTAP deletion is a target-indication pairing with eleven registered trials and eleven distinct sponsors, and no program has advanced past Phase 1. Of six Phase 1 trials in this specific PRMT5-by--tumor pairing, three completed and three terminated, a 50% termination rate, with three distinct sponsors exiting the pairing. The nearest direct comparator sharing both the PRMT5 target and the MTAP-deletion selection strategy is Bristol-Myers Squibb's BMS-986504 (navlimetostat), which has advanced into Phase 2 combination testing with pembrolizumab and chemotherapy in first-line metastatic NSCLC with homozygous MTAP deletion. Given that history, a program that clears Phase 1 with a defined recommended dose and without added toxicity beyond the chemotherapy backbone would be the result that moves this asset ahead of where half its Phase 1 predecessors in this pairing stopped. NCT07699757HSK41959 With Standard Therapy in Solid Tumors With MTAP DeletionNCT07699757
This analysis was produced using AI-assisted reporting systems, AppliedXL data, and official public records. These systems undergo editorial review, quality checks, and regular audits by human experts. Errors may still occur, as with any automated system. Always consult the linked primary sources. Read our AI Editorial Policy.