Ambros Therapeutics merges with Werewolf, raises $150M to fund phase 3 trial of rare disease drug

Ambros Therapeutics announced an all‑stock reverse merger with Werewolf Therapeutics, accompanied by a $150 million private placement. The transaction will see the combined company operate under the Ambros name and is intended to finance the next phase of its lead rare‑disease program.

Werewolf, which had emerged from stealth in 2021 and completed a $120 million IPO, saw its cash runway shrink to less than a year by early 2026. To address the shortfall, it sold assets to Jazz Pharmaceuticals and Merck KGaA while seeking a buyer for its Nasdaq listing.

Under the deal, former Werewolf shareholders will receive about 7 % of the new entity, with the remaining 93 % held by Ambros’ existing investors and participants in the new private placement. RA Capital Management and Janus Henderson Investors are co‑leading the financing.

Ambros projects that the combined cash resources will extend its runway into the first half of 2029, by which time it expects to report phase 3 data for its aminobisphosphonate candidate, neridronate, and file an FDA approval application.