Dr Hamid on the Rationale For Investigating Fianlimab Plus Cemiplimab in Melanoma

Omid Hamid, MD, director, Melanoma Program, The Angeles Clinic and Research Institute, Cedars-Sinai, discusses the rationale for a phase 1 trial of fianlimab (formerly REGN 3767) plus cemiplimab-rwlc (Libtayo) in patients with advanced melanoma who have received prior adjuvant PD-1 inhibitors.

Fianlimab is a LAG3 inhibitor, and cemiplimab is a PD-1 inhibitor. The combination of PD-1 inhibition and LAG3 inhibition has been shown to improve response rates and progression-free survival in patients with advanced melanoma, Hamid says. Initial data from this phase 1 trial were presented at the 2022 ESMO Congress. These data demonstrated a 64% overall response rate (ORR) in patients with advanced melanoma who were naive to PD-1 inhibition.

Updated findings from this trial, which were presented at the 2023 ASCO Annual Meeting, include follow-up data from the PD-1 inhibitor–naive population. The presentation also included novel data in a population of patients with pretreated melanoma, including those with prior exposure to adjuvant PD-1 inhibitors.

At a median follow-up of 11.5 months (interquartile range, 8.9-13.9), patients in the confirmatory PD-1 inhibitor–naive cohort (n = 40) achieved an ORR of 63% (95% CI, 46%-77%). The median duration of response (DOR) in this cohort was not reached (NR; 95% CI, not evaluable [NE]-NE), and the disease control rate (DCR) was 80% (95% CI, 64%-91%). Best overall responses of complete response (CR), partial response (PR), stable disease (SD), partial disease (PD), and NE were observed in 13%, 50%, 18%, 15%, and 5% of patients in this cohort, respectively.

At a median follow-up of 9.7 months (95% CI, 4.8-14.1), patients in the PD-1 inhibitor–experienced cohort (n = 18) achieved an ORR of 56% (95% CI, 31%-79%). The median DOR in this cohort was NR (95% CI, 6 months-NE), and the DCR was 67% (95% CI, 41%-87%). Best overall responses of CR, PR, SD, PD, and NE were observed in 6%, 50%, 11%, 28%, and 6% of patients in this cohort, respectively.