FDA Grants Fast Track Designation To Werewolf Therapeutics’ WTX-124 For Advanced Cutaneous Melanoma

Werewolf Therapeutics, Inc., a biotechnology company advancing innovative immunotherapies designed to activate the body’s immune system against cancer and immune-mediated diseases, announced that the U.S. Food and Drug Administration (FDA) has granted Fast Track Designation to WTX-124, a conditionally activated interleukin-2 (IL-2) INDUKINE™ therapy, for the treatment of patients with locally advanced or metastatic cutaneous melanoma who have progressed following standard immunotherapy. This designation highlights the potential of WTX-124 to address a significant unmet medical need, while facilitating closer regulatory engagement and accelerating development.

“At Werewolf, we are focusing on efforts to address the high unmet need of cancer patients, and we believe there is a significant opportunity with WTX-124 for the potential treatment of advanced cancers. We are encouraged by this Fast Track Designation as an important milestone for the WTX-124 program and because it underscores the urgent need for patients with relapsed/refractory melanoma where treatment options are limited. In the fourth quarter, we anticipate sharing preliminary data from the ongoing WTX-124 Phase 1/1b clinical trial, including in patients with cutaneous melanoma, and engaging with the FDA regarding the potential registration strategy for this agent,” said Daniel J. Hicklin, PhD, President and Chief Executive Officer of Werewolf. 

WTX-124 is currently being investigated in a Phase 1/1b open-label, multicenter clinical trial (NCT05479812) evaluating its use both as a monotherapy and in combination with pembrolizumab across multiple advanced solid tumor indications. Engineered to deliver IL-2 selectively within the tumor microenvironment, WTX-124 is designed to enhance anti-tumor immune activation while minimizing systemic toxicity commonly associated with traditional IL-2 therapies.

The FDA’s Fast Track program facilitates the development and review of investigational drugs that have shown potential to improve outcomes in serious or life-threatening conditions. Candidates with this designation benefit from priority review, rolling Biologics License Application (BLA) submissions, and potential accelerated approval pathways. The FDA granted Fast Track status to WTX-124 based on encouraging early data in cutaneous melanoma patients previously treated with checkpoint inhibitors, where the therapy demonstrated meaningful anti-tumor responses and a manageable safety profile. This designation positions Werewolf for more frequent and strategic interactions with the FDA to advance WTX-124’s clinical program.