Ambros Therapeutics Launches with $125 Million Series A Financing to Advance Neridronate Through Phase 3 Registrational Program for Complex Regional Pain Syndrome Type 1

• Neridronate granted FDA Breakthrough Therapy, Fast-Track, and Orphan Drug designations; pivotal Phase 3 trial planned to start in the first quarter of 2026
• Jay Hagan joins as Chief Executive Officer leading a seasoned late-stage development team and will serve on the Board alongside Co-Founder and Chairman Keith Katkin
• Oversubscribed Series A financing co-led by RA Capital Management and Patient Square Capital's platform Enavate Sciences with participation from a strong syndicate of dedicated life sciences investors

IRVINE, Calif., Dec. 16, 2025 /PRNewswire/ -- Ambros Therapeutics, Inc. today announced its launch as a clinical-stage biotechnology company advancing late-stage therapies for severe, underserved diseases beginning with neridronate for Complex Regional Pain Syndrome Type 1 (CRPS-1). Ambros launches with an oversubscribed $125 million Series A financing co-led by RA Capital Management and Patient Square Capital's platform Enavate Sciences, joined by Abiogen Pharma, Janus Henderson Investors, Arkin Bio, Balyasny Asset Management, Transhuman Capital, Adage Capital Partners LP, and other dedicated life sciences investors.

The financing is expected to support the neridronate pivotal Phase 3 clinical trial in CRPS-1 (CRPS-RISE) and related regulatory preparations and pre-commercial activities. Ambros licensed the rights to neridronate from the Italian pharmaceutical company, Abiogen Pharma S.p.A., under a strategic collaboration, providing Ambros with exclusive rights to neridronate in North America, with an option for broader market expansion.

Abiogen Pharma is a recognized leader in the discovery and development of bisphosphonates including the advancement of neridronate. Neridronate was approved in Italy based on the safety and efficacy demonstrated in two CRPS Phase 3 studies and has been used for CRPS and other disorders in more than 600,000 patients to date. 

The U.S. Food and Drug Administration (FDA) has granted neridronate Breakthrough Therapy, Fast Track, and Orphan Drug designations for the treatment of CRPS. CRPS-1, the subtype Ambros is targeting, is a severe, debilitating rare disease with an estimated 65,000 new cases annually in the United States.

"We are launching Ambros with a seasoned leadership team and a therapy that has been used to treat CRPS in Italy for over ten years," said Jay Hagan, Chief Executive Officer of Ambros Therapeutics. "With no approved medicines for CRPS-1 outside of Italy, we look forward to working with Abiogen Pharma to advance neridronate through Phase 3 and bring this therapy to patients who urgently need it."

"We are excited to partner with Ambros to bring neridronate to patients outside of Italy, where there are currently no approved medicines," said Massimo Di Martino, President of Abiogen Pharma. "With decades of leadership in bisphosphonate innovation at our dedicated research and development center, we believe in the potential for neridronate to address CRPS outside of Abiogen's core commercial markets."

In addition to Mr. Hagan, Ambros' leadership team includes Gail Cawkwell, M.D., Ph.D., Chief Medical Officer; Michael Cruse, Chief Operating Officer; Kunal Kishnani, Senior Vice President Corporate Development; and Jennifer Lam, Senior Vice President Finance and Administration.

The Board of Directors is chaired by industry veteran Keith Katkin, and includes Co-Founder Vivek Ramaswamy; Matthew Hammond, Ph.D., of RA Capital Management; Trit Garg, M.D., of Patient Square Capital; Prisca Di Martino of Abiogen Pharma; and Jay Hagan, Chief Executive Officer.

"Neridronate is one of the few late-stage programs with a well-established mechanism, extensive real-world experience, and the potential to meaningfully change the trajectory of CRPS-1," said Matthew Hammond, Partner at RA Capital Management. "We are pleased to support Ambros as it advances this important therapy through this pivotal program to potentially be available for patients with very few options to address this painful disease."

About Neridronate

Neridronate is a novel bisphosphonate that was discovered, developed, and commercialized by Abiogen Pharma S.p.A. for the Italian market. Neridronate is approved and marketed in Italy for the treatment of Complex Regional Pain Syndrome (CRPS); clinical studies have demonstrated lasting pain reduction along with improvements in other CRPS related symptoms. Beyond CRPS, neridronate is approved in Italy for additional indications including osteogenesis imperfecta and Paget's disease. Its well-established safety-profile and therapeutic benefits make it a potential promising treatment for patients with CRPS-1 worldwide. Recognizing its potential, the U.S. Food and Drug Administration (FDA) has granted neridronate Breakthrough Therapy, Fast Track, and Orphan Drug designations for the treatment of CRPS.

About Complex Regional Pain Syndrome Type 1 (CRPS-1)

Complex Regional Pain Syndrome Type 1 (CRPS-1; formerly known as RSD or Reflex Sympathetic Dystrophy) is a rare and debilitating condition following an injury or trauma to the bone. There are currently no FDA-approved medicines available to treat this high unmet need patient population. The condition is characterized by intense pain that can be continuous in the affected limb – typically in extremities such as the arm, leg, hand or foot. Patients with CRPS-1 experience an evolving condition commencing with a "warm" phase lasting approximately six to twelve months after an initial injury where inflammation causes the affected limb to become red, swollen, warm, and painful to a chronic "cold" phase, where the affected limb changes its presentation but still faces ongoing, debilitating pain.

About Ambros Therapeutics

Ambros Therapeutics, headquartered in Irvine, California, is a clinical-stage biotechnology company focused on the development of innovative and transformative medicines for diseases with high unmet medical need. Ambros' lead investigational program targets Complex Regional Pain Syndrome Type 1 (CRPS-1). The Phase 3 pivotal trial (CRPS-RISE) is on track to initiate enrollment in the first quarter of 2026 and represents a potential first-in-class approach to addressing a disease with no FDA-approved medicines.

About Abiogen Pharma S.p.A.

Abiogen Pharma is headquartered in Pisa, Italy. Since 1997, its business has spanned across several integrated areas: research and development, manufacturing of pharmaceuticals with its own brand or under third-party contracts, and marketing of own and licensed drugs. Its target therapeutic areas include bone metabolism, pain treatment, as well as respiratory, metabolic (diabetes) and dermatological disorders. In 2022, Abiogen Pharma started the internationalization process covering Germany and Switzerland to date. With approximately 168 million euros in revenue (2023) and approximately 460 employees, it ranks among the 15 largest Italian pharmaceutical companies.

Company Contact
Danielle Spangler
917-924-6752
[email protected] 

Media Contact:
David Schull
Russo Partners
 646-942-5588
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SOURCE Ambros Therapeutics