Combination treatment with an oncolytic virus plus a PD-1 inhibitor shows promise in patients with nonmelanoma skin cancers, researchers reported in early study results during the 2022 Multidisciplinary Head and Neck Cancers Symposium.
The findings are part of the ongoing multicohort IGNYTE trial of the oncolytic virus RP1 in patients with several different cancer types and diagnoses. The researchers reported data from a cohort of 28 patients with locally advanced or metastatic nonmelanoma cutaneous cancers of the head and neck: 15 with cutaneous squamous cell carcinoma, 5 with angiosarcoma, 4 with basal cell carcinoma, and 4 with Merkel cell carcinoma.
When treated with a combination of RP1 and nivolumab, 16 of the 28 patients achieved objective responses, including 7 complete responses in the 15 patients with cutaneous squamous cell carcinoma. The study endpoint is not yet reached, but some of the responses have persisted for two years. The most common grade 3 or higher adverse event was fatigue, which occurred in 5 of the 69 patients in the full, multicohort IGNYTE trial.
“Tumor regression has been observed in both injected and uninjected lesions, indicative of induction of a systemic immune response,” the researchers said. “In cutaneous squamous cell carcinoma, a particularly high rate of complete responses has been observed. The combination of RP1 plus nivolumab has shown clear evidence of durable clinical benefit in patients with nonmelanoma skin cancer of the head and neck.”