HOOKIPA Pharma Inc. announced it has entered into a clinical collaboration and supply agreement with Merck & Co., Inc., Kenilworth, NJ., USA (known as MSD outside of the United States and Canada) to evaluate the combination of HB-200, a novel arenaviral immunotherapeutic, and Merck & Co., Inc., Kenilworth, NJ., USAs anti-PD-1 therapy, KEYTRUDA® (pembrolizumab) as first-line treatment for patients with advanced head and neck squamous cell carcinoma (HNSCC). The collaboration has been initiated based on promising data from the ongoing HB-200 Phase 1/2 clinical trial (NCT04180215) in advanced HPV16+ cancers. As reported at the 2021 American Society of Clinical Oncology (ASCO) Annual Meeting, 15 patients with metastatic head and neck cancers were eligible for the efficacy analysis, as of data cut-off. HB-201 monotherapy showed an 18% overall response rate and median progression-free survival of 3.45 months in heavily pretreated head and neck cancer patients, better than current 2nd-line treatment. In addition, preliminary data on HB-201/HB-202 therapy showed a disease control rate of 100% (4/4 patients). Importantly, the Phase 1 data on 38 evaluable patients showed that HB-200 therapy has a favorable safety profile in heavily pre-treated patients with HPV16+ cancers, underlining its potential as a monotherapy and in possible combination with checkpoint inhibitors. With a HB-200 program data read-out anticipated by Fourth Quarter 2021, HOOKIPA anticipates initiating a Phase 2 trial with HB-200 in combination with KEYTRUDA in 2022. Additional Phase 2 expansion cohorts are also planned to start in First Quarter 2022.