Cullinan starts zipalertinib NDA filing under FDA RTOR program

Cullinan Therapeutics, Inc. (Nasdaq: CGEM) has begun the process of submitting a New Drug Application to the U.S. Food and Drug Administration for zipalertinib combined with platinum-based chemotherapy. The company filed this application under the FDA's Real-Time Oncology Review program, which allows sponsors to share clinical data before the full application is complete. This approach is intended to facilitate an earlier review of the drug's efficacy and safety results.

The submission relies on data from the Phase 3 REZILIENT3 trial, which met its primary endpoint. The study showed that adding zipalertinib to chemotherapy improved median progression-free survival in a statistically significant and clinically meaningful way compared to chemotherapy alone. Cullinan noted that this combination achieved the longest median progression-free survival seen so far in first-line EGFR exon 20 insertion non-small cell lung cancer. Researchers presented these findings at the International Association for the Study of Lung Cancer’s 2026 World Conference on Lung Cancer during a Presidential Symposium.

The company expects to finish the NDA submission by the end of 2026. Zipalertinib is an orally available small molecule designed to inhibit EGFR variants with exon 20 insertion mutations. The drug currently holds FDA Breakthrough Therapy designation for patients with locally advanced or metastatic EGFR exon 20 insertion NSCLC who have already received platinum-based chemotherapy. A separate application seeking accelerated approval for zipalertinib as a monotherapy in this second-line setting is currently with the FDA, with a target action date set for February 27, 2027.

Cullinan Therapeutics is positioned to receive $30 million in milestone payments if the second-line application is approved in the U.S., and $100 million if the first-line application is approved. Taiho Oncology, Inc., along with its parent company Taiho Pharmaceutical Co., Ltd., is developing zipalertinib in collaboration with Cullinan Therapeutics in the United States. The drug remains investigational and has not received approval from any health authority.