Early Results With Nivolumab Plus Oncolytic Virus in Non-Melanoma Skin Cancers
Posted: Monday, December 7, 2020
The combination of nivolumab and a relatively new agent—RP1—showed antitumor activity in patients with non-melanoma skin cancers, including cutaneous squamous cell carcinoma and angiosarcoma, according to interim results of an ongoing, open-label early-phase trial presented during the 2020 Society for Immunotherapy of Cancer (SITC) Annual Meeting (Abstract 422) and published in the Journal for ImmunoTherapy of Cancer. Mark Middleton, MD, PhD, of the University of Oxford, United Kingdom, and colleagues described RP1 as an enhanced potency oncolytic herpes simplex virus encoding a fusogenic protein and granulocyte-macrophage colony-stimulating factor. In previous work among patients with various types of cancer, RP1 promoted tumor regression alone, and with nivolumab and was relatively tolerable and safe, they noted.
Among the reported results were 13 patients with non-melanoma skin cancer who had not previously received an anti–PD-1 inhibitor and who were followed for more than 8 weeks on the RP1/nivolumab regimen. Of them, seven of eight patients with cutaneous squamous cell carcinoma and one of two with angiosarcoma achieved a response. Five of the responses in patients with cutaneous squamous cell carcinoma were deemed to be complete, for a complete response rate in this subgroup of 62.5%, including of uninjected visceral disease, the researchers stated.
“[Patients’] tumor biopsies continue to routinely show immune activation, including robust recruitment of CD8+ T cells, reversal of T-cell exclusion, and increased PD-L1 expression,” described Dr. Middleton and co-investigators. The participants received up to eight doses of RP1 (10 or fewer mL/visit every 2 weeks, with the first dose of 106 PFU/mL, then 107 PFU/mL); from the second RP1 dose on, they received RP1 with nivolumab (240 mg intravenously every 2 weeks for 4 months, then 480 mg intravenously every 4 weeks for up to 2 years).
Disclosure: For full disclosures of the study authors, visit jitc.bmj.com.