Exelixis, Inc. has announced a collaboration with Merck to conduct the STELLAR-316 trial, a Phase 3 pivotal study aimed at evaluating the efficacy of zanzalintinib in combination with KEYTRUDA QLEXTM (pembrolizumab and berahyaluronidase alfa-pmph) for patients with resected stage II/III colorectal cancer (CRC). This trial will specifically target patients who have tested positive for molecular residual disease (MRD+) following definitive therapy and have no radiographic evidence of disease. The primary endpoint of the trial will be disease-free survival, while secondary endpoints will include the clearance of circulating tumor DNA. Exelixis plans to initiate the trial in mid-2026, following a previous collaboration with Natera to utilize its SignateraTM assay for patient enrollment. Colorectal cancer remains a significant health concern, being the third most common cancer in the U.S., with an estimated 159,000 new diagnoses in 2026. Zanzalintinib is a novel oral kinase inhibitor that targets several oncogenic pathways, and its development program includes ongoing trials for various cancers. This collaboration represents a strategic step forward in advancing treatment options for patients at high risk of CRC recurrence.