Pasatru™ (garetosmab-grts) injection is the second treatment approved for people living with FOP in the United States

Today is an incredible day for the FOP community, which has been decades in the making! We want to start by thanking FOP community members from around the world who participated in the garetosmab trials. 

The U.S. Food & Drug Administration (FDA) has approved Regeneron Pharmaceuticals’ garetosmab for the treatment of fibrodysplasia ossificans progressiva (FOP) in the United States. It is the first drug approved for FOP shown to have an impact on both bone growth and flare-ups. 

Read Regeneron’s press release and see the label information. 

• The brand name of the drug is Pasatru™

• Pasatru (garetosmab-grts) injection reduces formation of new heterotopic ossification (HO) lesions and clinician-assessed flare-ups in adults with FOP. 

• The label for Pasatru indicates it may be prescribed to treat FOP in adults 18 years and older. Please click here for full Prescribing Information, including Medication Guide.

• Pasatru is a biologic drug invented by scientists at Regeneron who were looking for ways to treat FOP by blocking heterotopic bone growth. It is administered once a month during a one-hour infusion. According to the press release, "...Pasatru can be administered across a range of care settings, including home infusion where appropriate."

• Regeneron will soon release websites to support people with FOP and their local healthcare providers. 

• Pasatru is only available for treatment of FOP for individuals in the United States. 
  

• The European Medicines Agency (EMA) in the European Union is also reviewing Garetosmab.

THANK YOU

Garetsomab (now known as Pasatru) was tested in both the LUMINA-1 Phase 2 and the OPTIMA Phase 3 clinical trials. We are deeply grateful to the 44 people with FOP who participated in LUMINA-1 and the 63 who participated in the OPTIMA trial. 

We're also grateful to the Principal Investigators, Study Coordinators, and all of the staff at the trial sites who took such good care of our families.

We want to thank Regeneron and its employees for their long-standing commitment and dedication to the FOP community. We want to express our gratitude to the Regeneron scientists whose many years of work led to the discovery of garetosmab; and to the Clinical Development team and Clinical Operations teams who led the development of garetosmab as a treatment for FOP. 

Publications & Presentations

Multiple publications and presentations have reported results from the garetosmab trials. 

June 2026 presentations at ENDO 2026, the annual meeting of the Endocrine Society, where two posters and a talk were presented. 

• Safety and Efficacy of Garetosmab in Adults with FOP: Week 56 Results from the Phase 3 OPTIMA Study

• Inhibition of Activin A Stops the Regrowth of Surgically Resected Heterotopic Bone in a Mouse Model of FOP

• Assessing the Participant Experience with FOP: Qualitative Interviews from the OPTIMA Trial

September 19, 2025 press release of top-line results of the OPTIMA Trial

Journal of Bone & Mineral Research, August 31, 2024 (specifically discusses garetosmab’s impact on flare-ups)

A Plain Language Summary of the LUMINA-1 trial was published on April 11, 2024, to ensure that the trial results were understandable for FOP families. 

September 2023 publication in Nature Medicine and related press releases of peer-reviewed results of the Phase 2 LUMINA-1 Clinical Trial

The FOP community may also find these articles interesting: 

• Biomolecules, January 12, 2024 How Activin A Became a Therapeutic Target in FOP
• Science Translational Medicine, September 2, 2015 ACVR1R206H receptor mutation causes fibrodysplasia ossificans progressiva by imparting responsiveness to activin A 

Where is Pasatru Approved?

It is important to note that the FDA’s approval of Pasatru is only for adults aged 18 and older with FOP living in the United States. In Q1 2026, Regeneron announced that garetosmab had been accepted for review by the U.S. FDA and the EMA in the European Union. We await the EMA's decision.

In What Other Countries is Regeneron Seeking Approval of Garetosmab?

Pasatru™ previously received Fast Track designation and Orphan Drug Designation from the FDA, as well as Orphan Designation by the European Medicines Agency in the European Union and the Ministry of Health, Labour and Welfare in Japan.

Regeneron is in ongoing discussions with regulatory authorities in various countries about the approval of garetosmab. We communicate regularly with Regeneron and will share announcements with the FOP community when they are publicly available. 

Is Garetosmab in a Trial for Children? 

OPTIMA-2, a Phase 3 pediatric clinical trial, is now listed on clinicaltrials.gov, but the clinical trial is NOT YET RECRUITING. As soon as we have an announcement, we will inform the FOP community. 

If you would like to receive updates on clinical trials and drug reviews, please sign up for IFOPA’s Clinical Trial Alerts at ifopa.org/clinical-trial-alerts

About Garetosmab

FOP is caused by a mutation in a gene called ACVR1. This gene provides instructions for making a receptor protein ACVR1/ALK2. Normally, a protein called Activin A turns this receptor off. In people with FOP, the mutated receptor responds differently—Activin A turns it on, resulting in abnormal bone growth (heterotopic ossification, or HO).

Garetosmab is an antibody that attaches to Activin A and blocks its activity. By blocking Activin A, garetosmab is designed to prevent or reduce the abnormal bone growth associated with FOP.