U.S. FDA Does Not Approve Palovarotene Capsules as a Treatment for FOP

Today we have learned that the U.S. Food & Drug Administration has decided NOT to grant marketing authorization approval to Ipsen’s palovarotene capsules as a treatment for fibrodysplasia ossificans progressiva (FOP) in the United States.

We know this news is very disappointing for many in the FOP community, including trial participants and those that were hopeful that palovarotene would receive regulatory approval in their country. You can read Ipsen’s press release and a letter from CEO David Loew here.


We are grateful to every FOP family that participated in the Ipsen studies and trials, this includes the FOP Natural History Study and the MOVE trial. Whether you feel the drug was effective for you or not, your contribution matters. To the FOP families from around the world who made their voices heard by providing written or verbal testimony during the FDA Advisory Committee Meeting, thank you for your contributions as well.

We're also grateful to the Principal Investigators, Study Coordinators. and all of the staff at the trial sites that took such good care of our families. We also stop today and appreciate the researchers whose basic and translational research identified retinoids (e.g. palovarotene) as a potential treatment for FOP. Finally, we express our gratitude to both Clementia and Ipsen and their team members for their commitment to the FOP community and their tremendous investments in the development of palovarotene.

Where is SohonosTM Approved?

In January 2022, Health Canada approved palovarotene capsules (the brand name is SohonosTM) for adults and children aged 8 years and above for females and 10 years and above for males in Canada. The only other country where palovarotene is currently approved is the United Arab Emirates which extends approval to a drug that has been approved by another regulatory agency

It is important to note that while the decision of Health Canada says that Sohonos is a safe and effective treatment that can be prescribed for those with FOP that meet the age criteria outlined above, Medicare (Canada's national healthcare system) has not yet decided if they will pay for Sohonos. In Canada, this decision process by Medicare can take several years. 

In What Other Countries is Ipsen Seeking Approval of Palovarotene?

At this time, we do not know the future of the palovarotene program and if Ipsen will seek regulatory approval in other countries. We await announcements from Ipsen and will share with the FOP community when they are publicly available. 

PIVOINE Rollover Study

Those patients enrolled in the PIVOINE Rollover Study of palovarotene still have access to take the drug, but that access will end when the study is over. The Rollover Study is closed and is not accepting new patients.  

What Other Drugs Are in Clinical Trials for FOP?

What we know about drug development is that not every drug works the same for every person. As the announcements about palovarotene are made, you will hear some people say they felt it worked for them and others who felt it wasn’t effective or felt the side effects (or the risk of the side effects) weren’t worth continuing to take the drug.

While we are disappointed that palovarotene did NOT receive marketing authorization approval from the European Commission or the U.S. FDA, we are also grateful that patients have the opportunity to participate in clinical trials to test other drugs for FOP

There are currently 4 active phase 2 and 3 trials for drugs to treat FOP and we are seeing pharmaceutical companies bring drug trials to countries that have never had them before. If you have a local physician who might be interested in running an FOP trial, please contact us at [email protected].

FOP experts often say it will likely take a cocktail of drugs to treat FOP. It is critically important that the trials are filled with the required number of eligible FOP patients so that the safety and effectiveness of all of these drugs can be determined. We urge each person living with FOP to review the list of trials and locations and speak with their doctor or the Principal Investigator to see what might be available to them.

Some of the benefits of participating in a clinical trial include:

  • After the placebo period, you will receive the drug if the trial offers an open-label extended treatment period.
  • Regular visits with an FOP expert during the duration of a trial.
  • There is no cost for you to participate in a trial as the travel expenses of you and a caregiver are covered. These expenses include airfare or train, lodging, car service and a food allowance. If you don’t have a caregiver available to travel with you, one may be provided for you in some trials.
  • It is important to remember that clinical trials are not treatments. They are tests of potential drugs to treat FOP so you should discuss all potential risks and benefits with your doctor or the trial’s Principal Investigator.

For those living in the European Union or the United States where palovarotene won’t be available to be prescribed, participating in one of these trials may be your next best option and you will want to enroll before the available spots fill. Please consult your doctor or Principal Investigator to discuss your options.

For those in Canada, even though palovarotene has been approved, you may decide to forgo the approved treatment and participate in a drug trial where participants are needed and there is no cost to you to participate. Of note, you cannot take Sohonos and participate in a clinical trial at the same time because the investigators won’t know which drug is (or isn’t) working for you.

Here is a list of the 4 remaining drug trials; 3 of which are recruiting. The links below will take you to more information about each trial.

If you have questions about participating in a clinical trial, the IFOPA has created a set of frequently asked questions that you can read at ifopa.org/fop_faq.

In just 16 years (2006-2022), the FOP community has moved from the discovery of the gene that causes FOP to the approval of the first drug to treat FOP in Canada. Now we are watching 4 other drugs progress through phase 2 and 3 trials. We are grateful to those that have participated in clinical studies and trials and hope that as trials expand worldwide that each person living with FOP will explore their options.

If you live in a country where there is not a clinical trial or perhaps you are not eligible to participate based on your age or your FOP progression, you are still eligible to participate in critical FOP research through the FOP Registry. You can sign up at fopregistry.org. After you complete an Enrollment Survey you’ll be emailed a reminder to complete a Follow-Up Survey every 6 months. The Registry is available in English, French, German, Italian, Korean, Polish, Portuguese, Russian and Spanish. As a thank you for your participation, you’ll receive a $25 Visa Gift Card for each completed survey (some exclusions apply). Not sure if you’re already enrolled or have questions about the Registry? Email Sammi Kile, Real-World Evidence Manager, at [email protected].

It is important to note that you can still continue to participate in the FOP Registry even if you are in a clinical trial. Thank you to the extra special people who participate in both!

We share in your disappointment today but remain hopeful due to the level of drug development activity and clinical trials that continue to take place in FOP.

We are in this fight to end FOP with each of you for as long as it takes! Thank you for being our partner whether you are an FOP family, donor, fundraiser, researcher, clinician, or pharmaceutical company team member.




Megan Olsen
FOP Mom and IFOPA Board Chair

Michelle Davis
IFOPA Executive Director


Make a Difference

Donate Connect Fundraise

Already a Member? Sign In

Sign Up for FOP Connection, Our Monthly eNewsletter