EXEL Collaborates With Natera for Late-Stage Colorectal Cancer Study

Core Insights - Exelixis, Inc. (EXEL) has announced a collaboration with Natera (NTRA) for the STELLAR-316 study, a phase III trial evaluating zanzalintinib in patients with resected stage II/III colorectal cancer (CRC) [1][3] - Following the announcement, Exelixis' stock rose by 6% on January 7, and the shares have increased by 33.9% over the past year, outperforming the industry gain of 17.2% [1] Study Details - The STELLAR-316 study is set to begin in mid-2026 and will assess zanzalintinib, a novel oral kinase inhibitor, both alone and in combination with an immune checkpoint inhibitor [3][7] - Eligible patients for the trial are those with molecular residual disease (MRD)-positive CRC, as determined by Natera's Signatera test, after definitive therapy [3][4] - The primary endpoint of the study is disease-free survival, with a secondary endpoint focusing on the clearance of circulating tumor DNA [4][7] Zanzalintinib Development - Zanzalintinib is also being evaluated for advanced solid tumors, including CRC, kidney cancer, and neuroendocrine tumors [8] - Exelixis has submitted a new drug application (NDA) to the FDA for zanzalintinib in combination with Roche's Tecentriq for previously treated metastatic colorectal cancer, supported by positive results from the STELLAR-303 study [9][10] - The STELLAR-303 trial demonstrated a statistically significant reduction in the risk of death compared to Stivarga, with consistent overall survival benefits across various subgroups [10][11] Future Plans - Exelixis is planning additional pivotal trials for zanzalintinib, including studies in post-chemotherapy adjuvant CRC settings and high-grade recurrent meningiomas [12][13] - The company aims to expand its oncology portfolio beyond its lead drug, Cabometyx, which has recently received label expansion for treating neuroendocrine tumors [14]