The FDA has granted fast track designation to WTX-124, a conditionally activated interleukin-2 (IL-2) therapy, for patients with locally advanced or metastatic cutaneous melanoma after standard immunotherapy. WTX-124, designed to deliver IL-2 selectively to tumors and reduce systemic toxicity, is being studied as monotherapy and in combination with pembrolizumab in a phase 1/1b trial for advanced solid tumors.
Early data showed encouraging activity—five patients achieved objective responses, three of whom had no disease progression at the latest update. One patient in the monotherapy arm achieved a complete response lasting over a year off therapy, and two in the combination arm maintained responses for more than eight months, with one improving to a complete response.
The ongoing first-in-human trial is evaluating WTX-124 in patients with advanced or metastatic solid tumors, including melanoma, renal cell carcinoma, cutaneous squamous cell carcinoma, and non–small cell lung cancer. The study’s primary goals include assessing safety, tolerability, and response rates, while secondary endpoints measure duration of response, progression-free survival, and overall survival.
Werewolf Therapeutics, the drug’s developer, stated that the designation highlights the urgent need for better treatments in relapsed or refractory melanoma and plans to share preliminary trial results later this year.