Werewolf Therapeutics to merge with Ambros in $150M private placement

Werewolf Therapeutics (Nasdaq: HOWL) and Ambros Therapeutics announced a definitive all-stock merger agreement, accompanied by a $150 million oversubscribed private placement, according to a press release issued Aug. 21, 2026.

The combined company will operate under the Ambros Therapeutics name, headquartered in San Diego, and is expected to trade on Nasdaq under the ticker "AMBX." The transaction is expected to close by the first quarter of 2027, pending stockholder approvals and other customary closing conditions.

The merger values Ambros Therapeutics at $500 million and Werewolf Therapeutics at $47.5 million before the concurrent private placement. Upon closing, pre-merger Ambros stockholders are expected to hold approximately 71.7% of the combined company, private placement investors approximately 21.5%, and pre-merger Werewolf stockholders approximately 6.8%.

The private placement was co-led by RA Capital Management and Janus Henderson Investors, with participation from Aberdeen Investments, Adage Capital Partners, Balyasny Asset Management, and others. Proceeds are intended to fund operations through topline results from the ongoing CRPS-RISE Phase 3 clinical trial, expected in 2028, and a planned New Drug Application submission to the FDA, with cash runway projected into the first half of 2029.

The combined company's primary focus will be neridronate, a bisphosphonate being evaluated in the CRPS-RISE trial for Complex Regional Pain Syndrome Type 1 (CRPS-1). The FDA has granted neridronate Breakthrough Therapy, Fast Track, and Orphan Drug designations. Ambros Therapeutics has stated that alignment with the FDA suggests a single successful pivotal trial could potentially support approval. CRPS-1 affects an estimated 65,000 newly diagnosed patients in the United States annually, with no currently FDA-approved treatment.

Neridronate is approved in Italy for CRPS and other indications and has been administered to approximately 600,000 patients there. The combined company's leadership will be drawn from the current Ambros Therapeutics team, with Jay Hagan serving as chief executive officer.

You May Also Be Interested In

• Yarrow Bioscience prices $150M public offering at $26 per share
• Eastern International receives Nasdaq minimum bid price deficiency notice
• Yarrow Bioscience launches underwritten public stock offering