Ambros Therapeutics Secures Key Patent for Precision Medicine Approach to Treating Complex Regional Pain Syndrome
Key Insights
Ambros Therapeutics (search) received a Notice of Allowance from the USPTO (search) for a patent covering methods to selectively treat Complex Regional Pain Syndrome Type 1 (search) using neridronate, potentially extending exclusivity through 2045.
The patent covers a precision medicine approach combining positive triple-phase bone scans with specific warm CRPS-subtype attributes to identify patients likely to respond to neridronate treatment.
The company has initiated enrollment in its pivotal Phase 3 CRPS-RISE trial using these same patient selection criteria, targeting a rare disease with no FDA-approved treatments.
Ambros Therapeutics (search) announced that the United States Patent and Trademark Office (search) has issued a Notice of Allowance for a patent application covering methods to selectively treat patients with Complex Regional Pain Syndrome Type 1 (search) (CRPS-1 (search)) using neridronate. The patent strengthens the company's intellectual property portfolio and extends potential exclusivity for the orphan drug through 2045.
Novel Patient Selection Strategy
The allowed patent application, titled "Methods of Selectively Treating Complex Regional Pain Syndrome Type 1 (search) (CRPS-1 (search)) Using Bisphosphonate (search) Derivatives," was filed in July 2025. It covers a precision medicine approach that combines a positive triple-phase bone scan (TPBS) with specific attributes of the warm CRPS-subtype to identify patients likely to respond to neridronate treatment.
"Supported by innovative analyses of data, the methods of patient selection covered by this allowed patent application represent a novel precision medicine approach to identifying patients with CRPS-1 (search) who are likely to respond to neridronate," said Gail Cawkwell, M.D., Ph.D., Chief Medical Officer of Ambros Therapeutics (search). "By leveraging a positive triple-phase bone scan with specific clinical manifestations of CRPS-1, we believe we can identify patients that are significantly more likely to benefit from neridronate."
Pivotal Phase 3 Trial Underway
Ambros initiated enrollment in its pivotal CRPS-RISE (NCT07210515) Phase 3 clinical trial of neridronate in patients with CRPS-1 (search) in the first quarter of 2026. The trial uses the same patient selection characteristics covered by the patent as part of eligibility determination.
"The granting of this patent will mark an important step for Ambros and our orphan drug neridronate, and represents the potential for meaningful value creation among patients, investors and all stakeholders," said Jay Hagan, Chief Executive Officer of Ambros Therapeutics (search). "With an enhanced IP portfolio, we will be well-positioned to advance this important therapy through our pivotal program and potentially to patients with CRPS-1 (search) who are in urgent need of new treatment options."
Addressing High Unmet Medical Need
Complex Regional Pain Syndrome Type 1 (search), formerly known as Reflex Sympathetic Dystrophy (search), is a rare and debilitating condition that typically follows limb injury or trauma to the bone. There are currently no FDA-approved medicines available to treat this patient population. The condition is characterized by intense, continuous pain in the affected limb, typically in extremities such as the arm, leg, hand or foot.
Patients with CRPS-1 (search) often experience an evolving condition that begins with a "warm" phase lasting approximately six to twelve months, where inflammation causes the affected limb to become red, swollen, warm, and painful. In many patients, this progresses to a chronic "cold" phase with ongoing, debilitating pain.
Established Safety Profile and Regulatory Support
Neridronate is a bisphosphonate (search) discovered, developed, and commercialized by Abiogen Pharma S.p.A. (search) for the Italian market. The drug is approved and marketed in Italy for treating Complex Regional Pain Syndrome, with clinical studies demonstrating lasting pain reduction and improvements in other CRPS-related symptoms. Beyond CRPS, neridronate is approved in Italy for additional indications including osteogenesis imperfecta (search) and Paget's disease (search).
Recognizing its therapeutic potential, the U.S. Food and Drug Administration (search) has granted neridronate Breakthrough Therapy, Fast Track, and Orphan Drug designations for the treatment of CRPS. The drug's well-established safety profile and therapeutic benefits position it as a promising treatment for patients with CRPS-1 (search) worldwide.