FDA Grants Accelerated Approval to Lifileucel for Previously Treated Metastatic Melanoma

By: Dr. Anish Shah
Bronx-Lebanon Hospital; Bronx, NY

On February 16, 2024, the U.S. Food and Drug Administration granted accelerated approval to lifileucel (Amtagvi). The approval targets adults with metastatic or inoperable melanoma who have already received treatment with a PD-1 antibody and, if positive for BRAF V600, a BRAF inhibitor, with or without a MEK inhibitor.

Study ID: NCT02360579

Approval was based on the C-144-01 trial, a phase 2 study that included 73 patients with unresectable or metastatic melanoma previously treated with PD-1 antibody and BRAF inhibitor. Lifileucel was administered following a lymphodepleting regimen until tumor progression or unacceptable toxicity. The lymphodepleting regimen included daily doses of 60 mg/kg of cyclophosphamide with mesna for two days, followed by 25 mg/m2 of fludarabine daily for five days. Subsequently, lifileucel was introduced. To aid in cell expansion within the body, aldesleukin was administered at 600,000 IU/kg at intervals of 8 to 12 hours for a maximum of six doses, typically 3 to 24 hours post-infusion. On average, patients received a lifileucel dose of 21.1 × 109 viable cells and six doses of aldesleukin.

Efficacy was established on the objective response rate (ORR) and duration of response (DOR). The ORR was 31.5% (95% CI, 21.1%-43.4%), which included a complete response rate of 4.1% and a partial response rate of 27.4%. Of those who responded, 56.5%, 47.8%, and 43.5% continued to respond without tumor progression or death at 6, 9, and 12 months, respectively. The median treatment duration was not reached (NR; 95% CI, 4.1 months-NR). Side effects of the medication included chills, pyrexia, fatigue, tachycardia, diarrhea, febrile neutropenia, edema, rash hypotension, alopecia, infection, hypoxia, and dyspnea.

This approval represents a significant advancement in the treatment of unresectable or metastatic melanoma. Lifileucel, administered following a lymphodepleting regimen, has demonstrated a promising ORR and DOR among patients who have previously been treated with a PD-1 antibody and BRAF inhibitor. The FDA approval is based on the C-144-01 trial’s results and offers a novel T cell immunotherapy for patients with limited treatment options.