Fianlimab plus cemiplimab showed objective response rates of 20% to 33% in advanced solid tumors during a Phase 1 study.

This Phase 1, first-in-human study included the dose-expansion portion for patients with advanced non-small cell lung cancer, clear cell renal cell carcinoma, head and neck squamous cell carcinoma, and cutaneous squamous cell carcinoma. The population consisted of anti-PD-1/PD-L1 naive or experienced patients. The intervention was fianlimab 1600 mg plus cemiplimab 350 mg administered intravenously every 3 weeks. No comparator was reported.

The primary outcome was objective response rate per RECIST 1.1. In non-small cell lung cancer naive patients, the rate was 27% based on four partial responses. In non-small cell lung cancer experienced patients, the rate was 7% based on one partial response. In clear cell renal cell carcinoma naive patients, the rate was 20% based on three partial responses. In clear cell renal cell carcinoma experienced patients, the rate was 7% based on one partial response.

In head and neck squamous cell carcinoma naive patients, the rate was 33% based on five partial responses. In head and neck squamous cell carcinoma experienced patients, the rate was 7% based on one partial response. In cutaneous squamous cell carcinoma experienced patients, the rate was 20% based on two complete responses and one partial response. The follow-up duration was 0.7 months.

Adverse events included fatigue at 15%, rash at 12%, pruritus at 10%, infusion-related reaction at 10%, and adrenal insufficiency at 10%. Serious adverse events were not reported. Discontinuations were not reported. The tolerability was described as an acceptable safety profile. The study sample size was not reported. The setting was not reported. Funding or conflicts were not reported. Practice relevance was not reported.