Werewolf Therapeutics, Inc. (the Company or Werewolf) announced that the first patient has been dosed in a Phase 1/1b clinical trial evaluating WTX-124, the Company's lead INDUKINETM molecule targeting IL-2 for the treatment of solid tumors. The Phase 1/1b clinical trial is a first-in-human, multi-center, open-label trial that will evaluate WTX-124 as a monotherapy and in combination with KEYTRUDA (pembrolizumab), Merck's anti-PD-1 (programmed death receptor-1) therapy in patients with immunosensitive advanced or metastatic solid tumors who have failed standard of care, including checkpoint inhibitor therapy. The WTX-124 design consists of a wild-type IL-2 cytokine tethered to an inactivation domain to prevent activation in off-target tissue, a tumor protease-sensitive linker to allow for activation in the tumor micro-environment (TME) and a half-life extension domain to improve tumor exposure.

The selective release of IL-2 in the TME induces anti-tumor immune responses resulting in tumor regressions in preclinical models while minimizing the toxicities associated with systemic delivery of recombinant IL-2.