Zipalertinib Met Primary Endpoint in Lung Cancer Trial
The therapy combined with chemotherapy extended median progression-free survival by six months in Phase III testing.
Updated on Sept. 21, 2026 in Biotech
Live Poll
Do you trust biotech companies that pivot their primary business strategy while undergoing clinical trials?
Cullinan Therapeutics announced that its Phase III REZILIENT3 trial met its primary endpoint, showing zipalertinib plus platinum chemotherapy improved progression-free survival in patients. The results represent a clinical milestone for the targeted cancer therapy, which is currently undergoing regulatory review.
Why it matters
This result validates the efficacy of zipalertinib in treating lung cancer patients with specific mutations, potentially securing a new therapeutic option for those with limited treatment paths. By partnering with Taiho Pharmaceutical to offset oncology costs, the company is also pivoting its broader pipeline toward autoimmune research.
The REZILIENT3 trial demonstrated a median progression-free survival of 14.5 months for patients receiving zipalertinib plus chemotherapy, compared to 8.5 months for the control arm (hazard ratio of 0.50). The drug acts as a small-molecule tyrosine kinase inhibitor, specifically targeting EGFR exon 20 insertions.
The players
Cullinan Therapeutics
A Cambridge-based biotechnology firm focused on developing targeted oncology and autoimmune therapies with $356 million in cash.
Taiho Pharmaceutical
A Japanese research-based pharmaceutical company that partnered with Cullinan to co-develop the zipalertinib oncology program.
The details
Zipalertinib functions as a small-molecule tyrosine kinase inhibitor—a drug that blocks specific enzymes involved in cancer cell growth—designed to target epidermal growth factor receptor (EGFR) exon 20 insertions. In the REZILIENT3 trial, the therapy was administered in combination with platinum chemotherapy to improve outcomes. The company's separate pipeline asset, CLN-978, employs a T-cell engager format—a bispecific molecule that physically links immune cells to tumor cells—to facilitate the depletion of B-cells in patients with autoimmune diseases.
Timeline
February 2023: Cullinan licensed CLN-418 from Harbour BioMed.
2024: Company renamed from Cullinan Oncology to Cullinan Therapeutics.
June 2025: Cullinan in-licensed velinotamig for ex-China rights.
April 2026: FDA accepted the new drug application for zipalertinib.
13 September 2026: Phase III REZILIENT3 trial met its primary endpoint.
The Tech Race
Cullinan Therapeutics is positioning itself to compete in the precision oncology market while simultaneously diversifying into autoimmune disease. The trial results follow the FDA new drug application process, which governs how therapies move from late-stage trials to market entry.
Patients and clinicians are waiting for the final regulatory decision following the FDA's April 2026 acceptance of the company's new drug application. The outcome will determine when zipalertinib becomes a commercially available option for patients with EGFR exon 20 insertions.
The takeaway
This trial result significantly de-risks the primary oncology asset for Cullinan Therapeutics while providing the financial foundation to expand into autoimmune research. Stakeholders should watch for the official FDA regulatory decision on the new drug application to confirm market access timelines.
What happens next
The company expects to release additional readouts for its autoimmune pipeline by the end of 2026.
Further reading
For broader trends in clinical development and drug discovery, see our coverage of Biotech.
Source note: This article includes information reported by Thepharmaletter.
Live Poll
Do you trust biotech companies that pivot their primary business strategy while undergoing clinical trials?
