Exelixis presented detailed STELLAR-303 Phase 3 data showing its oral TKI zanzalintinib plus Roche’s Tecentriq reduced the risk of death by about 20% versus Stivarga in previously treated non‑MSI-high metastatic colorectal cancer. The company said it plans an NDA filing before year‑end based on the overall survival readout published in The Lancet and presented at ESMO. Investors initially cheered the OS signal but reacted to the granular data and toxicity profile: Exelixis shares dropped more than 10% on Monday as analysts weighed the magnitude of benefit against adverse events and competitive options. Exelixis executives stressed the survival result was consistent across subgroups and said a second regulatory endpoint readout (patients without liver metastases) will follow. The company plans to use the Phase 3 data package to support a U.S. filing later this year, positioning zanzalintinib as a potential new option in refractory colorectal cancer.