Regeneron Advances Garetosmab as Potential Second Treatment for FOP in the U.S.

What's Happening?

Regeneron is progressing with its drug candidate garetosmab, aiming to become the second approved treatment for fibrodysplasia ossificans progressiva (FOP) in the United States. The company has announced positive results from a phase 3 trial, showing that garetosmab, an anti-activin A antibody, significantly reduces the formation of new bone lesions in patients. This development comes as Regeneron plans to file for FDA approval by the end of the year. Currently, Ipsen's Sohonos (palovarotene) is the only FDA-approved treatment for FOP, a rare and debilitating condition affecting approximately 400 people in the U.S. Sohonos, however, has faced challenges due to its side-effect profile, leading to treatment discontinuation in some patients.

Why It's Important?

The introduction of garetosmab could significantly impact the treatment landscape for FOP, offering a new option for patients who have limited choices. The drug's potential to reduce new bone lesions by over 90% could improve the quality of life for those affected by this life-shortening disorder. The high cost of existing treatments, such as Sohonos, which is priced at $624,000 annually, underscores the need for competitive alternatives that could drive down costs and improve accessibility. Additionally, the success of garetosmab could encourage further research and development in the field of rare diseases, potentially leading to more innovative treatments.

What's Next?

Regeneron is expected to submit its application for FDA approval of garetosmab by the end of the year. If approved, the drug will join Sohonos as a treatment option for FOP, potentially leading to competitive pricing and broader access for patients. The independent data monitoring committee has recommended that all patients in the OPTIMA trial switch to garetosmab, indicating strong confidence in its efficacy. Meanwhile, Ipsen is developing a follow-up drug, fidrisertib, which is currently in phase 2 trials, suggesting ongoing advancements in FOP treatment options.