Phase I clinical trial of a recombinant oncolytic virus injection combined with PD-1 antibody-based gene therapy for recurrent head and neck cancer in China: An open-label study

This study aims to evaluate the safety and preliminary efficacy of VT1093, an oncolytic recombinant herpes simplex virus type 1 (HSV-1) engineered to express a PD-1 monoclonal antibody, for the treatment of recurrent head and neck cancer. This open-label, single-arm, dose-escalation Phase I clinical trial was an exploratory dose-escalation study, in which the dose is progressively increased in enrolled patients until either the maximum tolerated dose (MTD) or dose-limiting toxicity (DLT) is identified. Seven patients with recurrent head and neck cancer were recruited at Beijing Tongren Hospital. Patients received either a single or multiple intratumoral injections of VT1093. For the single-dose group, patients were monitored for 28 days after treatment. For the multiple-dose group, three treatments were administered biweekly, with a 28-day follow-up after the final injection. Treatment efficacy and adverse events were monitored and recorded throughout the study. Of the seven patients enrolled, five were eligible for efficacy evaluation. Two patients did not return for follow-up evaluation after treatment and were classified as treatment ineffective. Four patients achieved stable disease (SD), while one had progressive disease (PD), resulting in a disease control rate (DCR) of 57.1 % (4/7). The most common treatment-related adverse events were mild to moderate fever and fatigue (Grade 1-2), with no Grade 3 or higher events. A promising immune profile was found in response to the oncolytic virus injection combined with PD-1 antibody. The treatment was generally well tolerated, and no DLTs were observed. VT1093 shows promising efficacy in controlling disease progression in recurrent head and neck cancer, with a favorable safety profile and low toxicity. These results support further clinical development of VT1093 as a novel therapeutic approach for this patient population.