Exelixis, Inc. and MSD (tradename of Merck & Co., Inc., Rahway, N.J., USA) announced that the companies have entered into a clinical development collaboration to evaluate the combination of Exelixis’ investigational tyrosine kinase inhibitor (TKI) zanzalintinib with Merck’s anti-PD-1 therapy KEYTRUDA® (pembrolizumab) in a Phase 3 pivotal trial for the treatment of patients with head and neck squamous cell carcinoma (HNSCC), and zanzalintinib with WELIREG® (belzutifan), Merck’s oral hypoxia-inducible factor-2 alpha (HIF-2α) inhibitor, in a Phase 1/2 trial and two Phase 3 pivotal trials for the treatment of patients with renal cell carcinoma (RCC).