Werewolf Therapeutics Merges with Ambros to Develop CRPS-1 Treatment

Werewolf Therapeutics (HOWL) and Ambros Therapeutics announced their merger in an all-stock deal, forming a new company called AMBX. This combined entity will focus on developing neridronate, a treatment for Complex Regional Pain Syndrome Type 1 (CRPS-1), with the goal of bringing it to market.

The merger is valued at $500 million, with Ambros being the majority shareholder, holding around 71.7% of the combined company. Werewolf shareholders will own approximately 6.8%, while private placement investors will hold about 21.5%. The deal also secured a $150 million private placement led by RA Capital Management and Janus Henderson Investors.

Neridronate has already received FDA Breakthrough Therapy, Fast Track, and Orphan Drug designations. It is approved in Italy for CRPS and other conditions, with around 600,000 patients treated there. Ambros believes its intellectual property portfolio, combined with the Orphan Drug designation, could support U.S. market exclusivity through 2045.

In a separate transaction, Werewolf sold preclinical assets to EMD Serono for $33 million ($28 million upfront and $5 million after technology transfer). This deal allows Werewolf to retain rights needed to develop its WTX-124 and WTX-330 clinical programs.