Werewolf Therapeutics' Cancer Drug Shows Promise in Early Study for Solid Tumors, Stock Soars

Werewolf Therapeutics Inc HOWL released preliminary results from initial monotherapy dose-escalation cohorts of an ongoing Phase 1/1b trial of WTX-124 in patients with advanced or metastatic solid tumors.

The preliminary data will be presented at the Society for Immunotherapy of Cancer's Annual Meeting.

The preliminary data include data collected as of October 18, 2023, from 16 heavily pretreated patients from the first four monotherapy dose escalation cohorts (1, 3, 6, 12 mg). 

All treatment-emergent adverse events (TEAEs) were Grade 1 or Grade 2, and arthralgias (joint stiffness) and fatigue were the most common TEAEs. 

Vascular leak syndrome was not observed, and there were no dose-limiting toxicities, treatment-related serious adverse events (SAEs), or treatment-related study discontinuations.

WTX-124 showed expected pharmacokinetics with evidence of a wide therapeutic index allowing for continued dose escalation.

WTX-124 demonstrated both translational biomarker activity and early evidence of monotherapy antitumor activity at 6 mg and 12 mg doses.

CD8+ T and NK cell proliferation and activation in the tumor microenvironment and immune cell gene expression changes were seen at 6 mg and 12 mg dose levels.

Among five patients treated at 12 mg, one patient achieved an unconfirmed partial response, one patient had a restaging scan that was consistent with a partial response as of November 1, 2023, and one other showed evidence of antitumor activity.

Dose escalation is ongoing in the monotherapy and combination therapy arms of the trial, with additional data from monotherapy dose-escalation cohorts informing declaration of the recommended dose for expansion and opening of the monotherapy expansion arms expected in 1H of 2024.

Price Action: HOWL shares are up 18.60% at $2.55 during the premarket session on the last check Friday.