Other specialties

Fibrodysplasia ossificans progressiva: the approved drugs compared for prescribers

Atebrioz, Sohonos side by side on what each first fill waits on, what the label requires you to monitor and what an insurer asks to see, with FDA decisions, label changes and open trials for fibrodysplasia ossificans progressiva.

2prescribing guides ↓0FDA decisions pending ↓5open or opening studies ↓

November 9, 2026last checked

The 2 fibrodysplasia ossificans progressiva prescribing guides

One page per drug with the dispensing gate, prior authorization documentation, dosing, monitoring and interactions, each line sourced.

Atebrioz (zilurgisertib)Dosing, Pregnancy Testing, Interactions and PANo REMS; verify no pregnancy in females of reproductive potential, reconcile strong CYP3A4 inhibitors, CYP3A4 inducers and MATE1 or MATE2-K substrates, fax the MAP Patient Enrollment Form with both sides of the insurance card to 1-855-282-4884, and the MAP pharmacy confirms shipping before the first bottle.Open the Atebrioz prescribing guide →

Patient guide · Printable handout · Drug page

Sohonos (palovarotene)Pregnancy Rules, Growth X-rays, PA CriteriaEffective contraception from at least 1 month before the first dose and a negative serum pregnancy test within 1 week before it, in females of reproductive potential; baseline skeletal maturity in growing patients; IPSEN CARES enrollment, benefits verification and routing to a limited specialty pharmacy network.Open the Sohonos prescribing guide →

Patient guide · Printable handout · Drug page

The drugs side by side

Each cell is a summary of that drug's prescribing guide, which carries the full detail and a source on every line. Insurer thresholds are one public policy shown as an example; plans differ.

	Atebriozzilurgisertib	Sohonospalovarotene
Label dated	September 25, 2026	September 24, 2026
Starting dose	100mg (four 25mg tablets) orally once daily with or without food. Bottles hold 120 tablets with a child-resistant closure, a 30-day supply at this dose.	5mg once daily with food, preferably at the same time each day. Swallowed whole, or opened onto 1 teaspoon of soft food and taken within 1 hour. Stop daily dosing when flare-up dosing begins.
Dispensing gate	No REMS; verify no pregnancy in females of reproductive potential, reconcile strong CYP3A4 inhibitors, CYP3A4 inducers and MATE1 or MATE2-K substrates, fax the MAP Patient Enrollment Form with both sides of the insurance card to 1-855-282-4884, and the MAP pharmacy confirms shipping before the first bottle	Effective contraception from at least 1 month before the first dose and a negative serum pregnancy test within 1 week before it, in females of reproductive potential; baseline skeletal maturity in growing patients; IPSEN CARES enrollment, benefits verification and routing to a limited specialty pharmacy network. No REMS
Required monitoring	No scheduled labs in the label; pregnancy status before initiation, contraception through 1 week after the final dose, and review of any new CYP3A4 inhibitor, CYP3A4 inducer or MATE substrate	Pregnancy tests periodically and 1 month after stopping; growth and skeletal maturity every 6 to 12 months to final height; periodic spine imaging for vertebral fracture; mood and psychiatric symptoms; night vision
Example PA threshold	No public payer policy found as of November 9, 2026; Mirum's checklist for plans without a policy: genetic test results, CT or MRI, chart notes on HO volume and location, CAJIS and flares, FOP drug history, and an endocrinologist, rheumatologist, geneticist, orthopedic or bone specialist	Cigna example: female 8 or older or male 10 or older, a documented ACVR1 R206H genetic test, radiologically confirmed heterotopic ossification, an endocrinologist or bone disease specialist; 1-year approval
Support line	Mirum Access Plus, 1-855-676-4968 (1-855-MRM-4YOU), Monday to Friday 8 AM to 8 PM Eastern, enrollment fax 1-855-282-4884, as little as $0 per fill for eligible commercial or private insurance, a Patient Assistance Program, and Urgent Patient Access of 15-day supplies up to 60 days	IPSEN CARES, 866-435-5677, Monday to Friday 8 AM to 8 PM ET, Patient Access Managers for benefits verification and PA, copay as little as $0 for commercial plans, a Patient Assistance Program for the uninsured or functionally uninsured, and specialty pharmacy triage

Atebrioz zilurgisertib

Label dated: September 25, 2026
Starting dose: 100mg (four 25mg tablets) orally once daily with or without food. Bottles hold 120 tablets with a child-resistant closure, a 30-day supply at this dose.
Dispensing gate: No REMS; verify no pregnancy in females of reproductive potential, reconcile strong CYP3A4 inhibitors, CYP3A4 inducers and MATE1 or MATE2-K substrates, fax the MAP Patient Enrollment Form with both sides of the insurance card to 1-855-282-4884, and the MAP pharmacy confirms shipping before the first bottle
Required monitoring: No scheduled labs in the label; pregnancy status before initiation, contraception through 1 week after the final dose, and review of any new CYP3A4 inhibitor, CYP3A4 inducer or MATE substrate
Example PA threshold: No public payer policy found as of November 9, 2026; Mirum's checklist for plans without a policy: genetic test results, CT or MRI, chart notes on HO volume and location, CAJIS and flares, FOP drug history, and an endocrinologist, rheumatologist, geneticist, orthopedic or bone specialist
Support line: Mirum Access Plus, 1-855-676-4968 (1-855-MRM-4YOU), Monday to Friday 8 AM to 8 PM Eastern, enrollment fax 1-855-282-4884, as little as $0 per fill for eligible commercial or private insurance, a Patient Assistance Program, and Urgent Patient Access of 15-day supplies up to 60 days

Sohonos palovarotene

Label dated: September 24, 2026
Starting dose: 5mg once daily with food, preferably at the same time each day. Swallowed whole, or opened onto 1 teaspoon of soft food and taken within 1 hour. Stop daily dosing when flare-up dosing begins.
Dispensing gate: Effective contraception from at least 1 month before the first dose and a negative serum pregnancy test within 1 week before it, in females of reproductive potential; baseline skeletal maturity in growing patients; IPSEN CARES enrollment, benefits verification and routing to a limited specialty pharmacy network. No REMS
Required monitoring: Pregnancy tests periodically and 1 month after stopping; growth and skeletal maturity every 6 to 12 months to final height; periodic spine imaging for vertebral fracture; mood and psychiatric symptoms; night vision
Example PA threshold: Cigna example: female 8 or older or male 10 or older, a documented ACVR1 R206H genetic test, radiologically confirmed heterotopic ossification, an endocrinologist or bone disease specialist; 1-year approval
Support line: IPSEN CARES, 866-435-5677, Monday to Friday 8 AM to 8 PM ET, Patient Access Managers for benefits verification and PA, copay as little as $0 for commercial plans, a Patient Assistance Program for the uninsured or functionally uninsured, and specialty pharmacy triage

FDA decisions for fibrodysplasia ossificans progressiva

From the Trial Friend FDA decision calendar, which records each date from the sponsor's or the FDA's own announcement.

September 25, 2026Zilurgisertib (Atebrioz), NDA, Mirum Pharmaceuticals / IncyteApproved
August 19, 2026Pasatru (garetosmab), BLA, RegeneronApproved

Recent label changes

What changed in each label revision, from the FDA's approval letters and the labels' own revision lists.

September 2026Sohonos. The dosing section now says several 1mg, 1.5mg or 5mg capsules should not replace a single 10mg capsule. A study in 72 healthy volunteers found peak blood levels 31% higher with four 2.5mg capsules than with one 10mg capsule. FDA label
September 2026Atebrioz. This first label has no recent major changes, no boxed warning and one contraindication, pregnancy. The label carries a single revision date, September 2026, and no later changes. FDA label
September 2026Atebrioz. The FDA said Atebrioz received fast track, priority review and orphan drug designations. It called Atebrioz the third approved treatment for fibrodysplasia ossificans progressiva. FDA announcement
September 2026Atebrioz. The FDA approved Atebrioz on September 25, 2026, for adults and children 12 and older with FOP. The approval letter also granted Incyte a rare pediatric disease priority review voucher. FDA letter
March 2025Sohonos. The FDA approved a supplement on March 13, 2025, and the Medication Guide in use today carries a March 2025 date. The approval letter could not be opened for this page, so the changes are not described here. Drugs@FDA
August 2023Sohonos. The FDA approved Sohonos for FOP on August 16, 2023, with no REMS. It required a long-term safety registry that also collects information on pregnancies during treatment. FDA letter

Open trials

studies listing Fibrodysplasia Ossificans Progressiva are recruiting or about to open on ClinicalTrials.gov

Counted live, at most once a day

Screen a patient against them

Questions prescribers ask about Fibrodysplasia ossificans progressiva

Which Fibrodysplasia ossificans progressiva drugs require a REMS?

None of the 2 Fibrodysplasia ossificans progressiva drugs on this page has a REMS: Atebrioz and Sohonos. Each prescribing guide lists what does gate the first fill.

What monitoring do Fibrodysplasia ossificans progressiva drugs require?

Atebrioz: No scheduled labs in the label; pregnancy status before initiation, contraception through 1 week after the final dose, and review of any new CYP3A4 inhibitor, CYP3A4 inducer or MATE substrate. Sohonos: Pregnancy tests periodically and 1 month after stopping; growth and skeletal maturity every 6 to 12 months to final height; periodic spine imaging for vertebral fracture; mood and psychiatric symptoms; night vision.

What do insurers require before covering Atebrioz and Sohonos?

Each answer below is one public insurer policy, an example rather than every plan. Atebrioz: No public payer policy found as of November 9, 2026; Mirum's checklist for plans without a policy: genetic test results, CT or MRI, chart notes on HO volume and location, CAJIS and flares, FOP drug history, and an endocrinologist, rheumatologist, geneticist, orthopedic or bone specialist. Sohonos: Cigna example: female 8 or older or male 10 or older, a documented ACVR1 R206H genetic test, radiologically confirmed heterotopic ossification, an endocrinologist or bone disease specialist; 1-year approval.

Which support programs start Fibrodysplasia ossificans progressiva patients on therapy?

Atebrioz: Mirum Access Plus, 1-855-676-4968 (1-855-MRM-4YOU), Monday to Friday 8 AM to 8 PM Eastern, enrollment fax 1-855-282-4884, as little as $0 per fill for eligible commercial or private insurance, a Patient Assistance Program, and Urgent Patient Access of 15-day supplies up to 60 days. Sohonos: IPSEN CARES, 866-435-5677, Monday to Friday 8 AM to 8 PM ET, Patient Access Managers for benefits verification and PA, copay as little as $0 for commercial plans, a Patient Assistance Program for the uninsured or functionally uninsured, and specialty pharmacy triage.

A reference for licensed professionals, checked on November 9, 2026. Labels and plan policies change; the label on DailyMed and the plan's current policy govern. Not medical advice. For patients: the Fibrodysplasia ossificans progressiva page and the first 90 days pages for Atebrioz, Sohonos.