STELLAR-316 is a planned phase 3 pivotal trial in patients with resected stage II/III colorectal cancer (CRC). Under the terms of the clinical development collaboration with Merck, Exelixis is sponsoring the STELLAR-316 pivotal trial, and Merck will supply KEYTRUDA QLEX.
"This collaboration with Merck for the STELLAR-316 trial reflects the continued progress of the zanzalintinib clinical development program and is an important step forward in our efforts to advance a potentially new treatment option that may help prevent or delay metastatic progression for patients with resected colorectal cancer," said Dana T. Aftab, Ph.D., Executive Vice President, Research and Development, Exelixis. "We look forward to initiating the clinical trial to evaluate this novel combination, with the goal of enhancing treatment strategies and meaningfully improving clinical outcomes for patients with this form of cancer who face a high risk of recurrence."
STELLAR-316 is a planned phase 3 pivotal trial that will evaluate zanzalintinib with and without KEYTRUDA QLEX in patients with resected stage II/III CRC who, following definitive therapy, have tested positive for molecular residual disease (MRD+) and have no radiographic evidence of disease. The primary endpoint of the trial will be disease-free survival, with key secondary endpoints including circulating tumor DNA clearance. In January 2026, Exelixis announced a collaboration with Natera, a global leader in cell-free DNA and precision medicine, for STELLAR-316. Natera will provide its Signatera™ assay to identify MRD+ patients for trial enrollment. Exelixis expects to initiate STELLAR-316 in mid-2026.