Initiation of the STELLAR-305 phase II/III pivotal trial evaluating zanzalintinib + pembrolizumab in patients with previously untreated recurrent or metastatic head and neck cancer

“We are excited to progress zanzalintinib, our next-generation multi-targeted tyrosine kinase inhibitor, into this population of patients who otherwise are relegated to immunotherapy plus chemotherapy, but may benefit from a chemo-free option,” said Amy Peterson, M.D., Executive Vice President, Product Development & Medical Affairs, and Chief Medical Officer, Exelixis. “This study is based on encouraging data from a phase II investigator-initiated trial of cabozantinib and pembrolizumab and demonstrates our agility to move quickly into indications with sound rationale from our flagship asset.”

STELLAR-305 is a global, multicenter, randomized, double-blind phase II/III study that will enroll patients with PD-L1-positive recurrent or metastatic SCCHN that is incurable with local therapies. Patients must not have received prior systemic therapy for recurrent or metastatic disease. Patients will be randomized 1:1 to receive zanzalintinib in combination with pembrolizumab or placebo in combination with pembrolizumab. The primary endpoints of the study are progression-free survival (PFS) per Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 by Blinded Independent Radiology Committee (BIRC) and overall survival. Secondary endpoints include PFS per RECIST 1.1 by investigator and objective response rate and duration of response per RECIST 1.1 by BIRC and by investigator.