Vaccinex Inc., a clinical-stage biotechnology company, has entered into a clinical collaboration agreement with Merck through a subsidiary, to evaluate the combination of Vaccinex’s investigational SEMA4D inhibitor, pepinemab, and Merck’s anti-PD-1 therapy, Keytruda (pembrolizumab), in the treatment of patients with advanced, recurrent or metastatic head and neck squamous cell carcinoma (HNSCC).
 
“We are pleased to be working with Merck to evaluate the potential of pepinemab in combination with Keytruda to further improve the efficacy of cancer immunotherapy,” said Maurice Zauderer, Ph.D., president and chief executive officer of Vaccinex. “Several prior studies suggest that inhibition of SEMA4D increases immune infiltration and alters the balance of cytotoxic and immunosuppressive cells in the tumor microenvironment. SEMA4D is highly expressed in HNSCC and is believed to promote correspondingly high levels of myeloid derived suppressor cells. This collaboration provides an opportunity to evaluate this innovative approach in combination with anti-PD-1 therapy.” 
 
The planned clinical collaboration with pepinemab and pembrolizumab will consist of a dose escalation phase followed by an expansion phase that will enroll up to 65 HNSCC patients allocated to different levels of combined positive score (CPS) of PD-L1 expression. CPS is a biomarker associated with benefit in response to immunotherapy, and a major goal of this study is to determine whether combination therapy can improve response in these populations.  Key endpoints of the study include objective response, progression free survival and overall survival.