Combination RP1 and nivolumab can produce durable responses in patients with non-melanoma skin cancer of the head and neck, according to research presented at the 2022 Multidisciplinary Head and Neck Cancers Symposium.
RP1 is an enhanced oncolytic herpes simplex type 1 virus expressing a fusogenic glycoprotein and granulocyte macrophage colony stimulating factor, explained Jiaxin Niu, MD, PhD, of Banner MD Anderson Cancer Center in Gilbert, Arizona, when presenting the research at the meeting.
Researchers are testing RP1 alone or in combination with nivolumab in patients with solid tumors in the phase 2 IGNYTE trial (ClinicalTrials.gov Identifier: NCT03767348).
Dr Niu presented results with RP1 plus nivolumab in 28 patients with non-melanoma skin cancer who did not have prior exposure to anti-PD1/PD-L1 therapy.
The cohort included 15 patients with cutaneous squamous cell carcinoma (CSCC), 4 with basal cell carcinoma (BCC), 4 with Merkel cell carcinoma (MCC), and 5 with angiosarcoma.
In patients with CSCC, the objective response rate (ORR) was 60%, and the complete response rate was 46.6%.
“The complete remission rate for the combo is remarkable, 7 out of 15, almost 50%,” Dr Niu said in an interview. “This is unprecedented, albeit it is a small cohort of patients.”
The ORR in was 25% in BCC patients, 75% in MCC patients, and 66% in angiosarcoma patients. None of these patients had complete responses.
For the entire cohort, the median duration of response has not been reached, with some responses exceeding 2 years.
The most common adverse events were pyrexia (33.3%), chills (30.4%), fatigue (29%), pruritus (26.1%), influenza-like illness (24.6%), and nausea (21.7%).
There was 1 fatal adverse event (immune-mediated myocarditis), which was attributed to nivolumab.
Disclosures: This research was supported by Replimune Inc. Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.
Niu J, Milhem M, Vanderwalde AM, et al. Safety and efficacy of RP1 + nivolumab in patients with non-melanoma skin cancer of the head and neck: Results from IGNYTE phase 1/2 multi-cohort clinical trial. Multidisciplinary Head and Neck Cancers Symposium 2022. February 24- 26, 2020. Abstract 12.
This article originally appeared on Cancer Therapy Advisor