Werewolf Therapeutics will merge with Ambros Therapeutics in an all-stock transaction valued at $150 million, with the combined entity to be named Ambros Therapeutics and operate from San Diego.
The merger agreement includes a concurrent private placement led by RA Capital Management and Janus Henderson Investors, bringing total pre-closing valuations to $500 million for Ambros and $47.5 million for Werewolf. Following the deal, Ambros shareholders will retain approximately 71.7% ownership, private placement investors will hold about 21.5%, and Werewolf shareholders will account for roughly 6.8% of the combined company, subject to adjustments for Werewolf’s net cash at closing.
The combined company will focus on advancing Ambros’s neridronate program for Complex Regional Pain Syndrome Type 1 (CRPS-1), a condition with no FDA-approved treatments. Neridronate has received FDA Breakthrough Therapy, Fast Track, and Orphan Drug designations, and is being evaluated in the CRPS-RISE Phase 3 trial, an FDA-aligned study enrolling approximately 270 participants. Topline results are expected in 2028.
Ambros Therapeutics will continue trading under the ticker AMBX, while Werewolf’s current NASDAQ listing under HOWL will be delisted. The merger is expected to close in the first quarter of 2027, pending stockholder approval and customary closing conditions.
