FDA extends review of Exelixis’ zanzalintinib plus atezolizumab for metastatic colorectal cancer, with a decision expected March 3, 2027.
Written By: Mayuri Vaja, PharmD
Reviewed By: Pharmacally Editorial Team
The U.S. Food and Drug Administration has extended its review of Exelixis’ zanzalintinib plus Tecentriq (atezolizumab) for previously treated metastatic colorectal cancer, moving the expected regulatory decision to March 3, 2027. The agency classified newly submitted safety and efficacy information as a major amendment, requiring additional review time.
FDA Requests Additional Information
The review extension follows an FDA request for additional information related to the application. Exelixis submitted updated safety and efficacy data in response, shifting the anticipated action date from December 2026 to March 2027. The application covers zanzalintinib in combination with Roche’s Tecentriq for a subset of adults with previously treated metastatic colorectal cancer.
The extension does not indicate an approval or rejection. The FDA will assess the updated data as part of its ongoing review of the complete application.
Zanzalintinib Targets Multiple Kinase Pathways
Zanzalintinib is an oral tyrosine kinase inhibitor that targets VEGF receptors, MET, and the TAM family kinases TYRO3, AXL, and MER. These signaling pathways contribute to tumor growth, survival, progression, and the tumor microenvironment.
The combination pairs this multi-kinase activity with atezolizumab, an immune checkpoint inhibitor targeting PD-L1. Exelixis is also evaluating zanzalintinib across additional cancer indications as it expands its oncology pipeline.
STELLAR-303 Met Its ITT Overall-Survival Endpoint
The Phase 3 STELLAR-303 trial evaluated zanzalintinib plus atezolizumab against regorafenib in previously treated metastatic colorectal cancer. The study incorporated two dual primary overall-survival endpoints: OS in the intention-to-treat population and OS in patients without active liver metastases.
The ITT analysis met its primary endpoint, demonstrating a statistically significant overall-survival improvement with zanzalintinib plus atezolizumab versus regorafenib.
The second dual primary endpoint, OS in patients without active liver metastases, also favored the combination numerically but did not reach statistical significance. In the final analysis, median OS was 15.9 months versus 12.7 months with regorafenib, with a stratified hazard ratio of 0.83 (95% CI, 0.66-1.05; P=0.1185).
These findings provide important context for the FDA review. The trial therefore showed a statistically significant OS benefit in the broader ITT population, while the predefined population without active liver metastases showed a favorable numerical trend that did not meet the statistical threshold.
March 2027 Becomes the Next Regulatory Milestone
Zanzalintinib remains an important development program for Exelixis as the company works to expand its oncology portfolio beyond Cabometyx (cabozantinib). The drug continues to advance through studies in additional cancer types.
The FDA is now expected to issue its decision on the colorectal cancer application by March 3, 2027. Until then, the combination remains investigational for the proposed population. The final outcome will depend on the agency’s assessment of the complete application, including the newly submitted safety and efficacy information.
Reference
Exelixis SEC Filing, 10 SEPTEMBER 2026
About the Writer
Mayuri Vaja (Linkedin) is a Pharm.D professional with a strong interest in clinical research, pharmacovigilance, and medical writing, supported by certifications in pharmacovigilance and academic projects exploring AI in healthcare and drug safety.
With a growing focus on evidence-based healthcare and scientific communication, she is developing expertise in clinical research and translating healthcare evidence into clear, meaningful content.
As a Pharmacally healthcare writer, Mayuri is committed to creating accurate, research-driven, and clinically relevant healthcare content while continuously strengthening her professional skills.