Sohonos
Sohonos (palovarotene) is the first medication FDA-approved to treat a rare, genetic condition called fibrodysplasia ossificans progressiva (FOP). It's available as a capsule that's taken by mouth once daily with food. Because of the risk of serious birth defects, people who can get pregnant need to use birth control before, during, and after treatment. Common side effects include dry skin, itching, chapped lips, and joint pain.
What is Sohonos (palovarotene)?
What is Sohonos (palovarotene) used for?
Treatment of fibrodysplasia ossificans progressiva (FOP) in:
Females 8 years of age and older
Males 10 years of age and older
How Sohonos (palovarotene) works
Sohonos (palovarotene) is a retinoid. It lowers the amount of new abnormal bone growth in people with fibrodysplasia ossificans progressiva (FOP) by blocking an important process involving bone morphogenetic proteins (BMPs).
People with FOP have mutated BMPs that cause bones to grow in areas that don't typically have bones, such as muscles, ligaments, and tendons. Sohonos (palovarotene) helps to lower the amount of abnormal bone growth, which then helps to improve movement and relieve symptoms of FOP.
Drug Facts
Get your GoodRx coupon
What are the side effects of Sohonos (palovarotene)?
Common Side Effects
- Dry skin (57-61%)
- Itching (34-48%)
- Dry or chapped lips (38-47%)
- Joint pain (31-36%)
- Skin redness (19-32%)
- Rash (28-30%)
- Hair loss (24-30%)
- Pain in hands and feet (28-29%)
- Skin peeling (15-29%)
- Dry eye (10-22%)
Other Side Effects
- Nausea
- Back pain
- Headache
- Muscle pain
- Swelling in the arms and legs
- Feeling tired
Serious Side Effects
- Suicidal thoughts and behavior
- Serious skin reaction: skin pain, rash, fever, blisters, peeling skin
Source: DailyMed
The following side effects have also been reported
Side effects that you should report to your care team as soon as possible:
- Allergic reactions—skin rash, itching, hives, swelling of the face, lips, tongue, or throat
- Change in vision
- Mood and behavior changes—anxiety, nervousness, confusion, hallucinations, irritability, hostility, thoughts of suicide or self-harm, worsening mood, feelings of depression
Side effects that usually do not require medical attention (report these to your care team if they continue or are bothersome):
- Bone, joint, or muscle pain
- Dryness or irritation of the eyes, lips, mouth, or nose
- Hair loss
- Skin reactions on sun-exposed areas
Pros and cons of Sohonos (palovarotene)
Pros
The first and currently only treatment for FOP
Can open capsule and mixed with yogurt, applesauce, or oatmeal for people with difficulty swallowing pills
Shown to lower abnormal bone growth by more than 50% in people with FOP
Cons
Can cause serious birth defects so it's not safe in pregnancy
Not a good choice if you have a history of mental health problems including depression, hallucinations, or suicidal thoughts
Interacts with many medications, such as vitamin A and tetracyclines
Pharmacist tips for Sohonos (palovarotene)
Take Sohonos (palovarotene) by mouth with food at the same time each day can help your body absorb the medication better.
If you have trouble swallowing, open the Sohonos (palovarotene) capsule and sprinkle the contents onto a teaspoon (5 mL) of soft food (e.g., applesauce, yogurt, oatmeal). Make sure to take the mixture within 1 hour.
Don't eat or drink juices containing grapefruit or pomelo during treatment with Sohonos (palovarotene). Doing so can cause the body to absorb more of this medication, causing greater risk of side effects.
If you miss a dose of Sohonos (palovarotene), take the dose as soon as you remember. If it's been more than 6 hours since you missed a dose, just skip it and take your next dose as scheduled. Don't take two doses at the same time to make up for missed doses.
Sohonos (palovarotene) can cause you to sunburn more easily. To lower your risk, make sure to limit or avoid sun exposure during treatment with Sohonos (palovarotene). Wear protective clothing when outside, even on overcast days.
Sohonos (palovarotene) can cause you to have trouble seeing at night. Don't drive at night until you know how this medication affects your vision.
Avoid donating blood while taking Sohonos (palovarotene) and for a week after stopping the medication. This is to prevent pregnant people from accidentally receiving your blood donations since this medication is harmful to unborn babies.
Let your provider know if you experience symptoms of depression or worsening mood while taking Sohonos (palovarotene). In cases of serious depression, your provider might ask you to stop taking this medication.
Sohonos (palovarotene) can interact with some medications. Let your provider or pharmacist know what medications you're taking, including over-the-counter products and supplements, before you start Sohonos (palovarotene). Your provider might adjust your dose of Sohonos (palovarotene) to help you avoid side effects.
More tips for people who can get pregnant:
Use an effective form of birth control while you're taking Sohonos (palovarotene) since it can cause serious birth defects. Talk to your healthcare provider about appropriate forms of birth control.
You mustn't get pregnant a week before starting, during, and 1 month after treatment with Sohonos (palovarotene). Your provider will require you to get pregnancy tests done throughout your treatment.
Frequently asked questions about Sohonos (palovarotene)
How to save using GoodRx
What are the risks and warnings for Sohonos (palovarotene)?
Sohonos (palovarotene) can cause some serious health issues. This risk may be even higher for certain groups. If this worries you, talk to your doctor or pharmacist about other options.
Harm to unborn baby
Sohonos (palovarotene) can cause serious birth defects to unborn babies. If you can get pregnant, your provider will ask you to take a pregnancy test a week before starting Sohonos (palovarotene), periodically during treatment, and a month after stopping this medication. Make sure to use an effective contraception (e.g., condom, birth control pills) starting a month before your first dose and up to a month after your last dose. If you become pregnant or think you might be pregnant while taking Sohonos (palovarotene), stop treatment right away and speak to your provider.
Bone growth problems in children
Risk factor: Young children
Sohonos (palovarotene) can cause the growth plate to close early in children with FOP. This can cause some children to stop growing during treatment. Before starting Sohonos (palovarotene), your child's provider will examine your child to make sure their growth is normal. They'll continue to monitor your child's growth and height every 6-12 months during treatment with this medication. If your child's growth seems to have slowed down during treatment with Sohonos (palovarotene), let your child's provider know. They might ask your child to stop the medication until they're finished growing.
Severe skin reactions
Risk factors: History of skin problems | High dose of Sohonos (palovarotene) | Excessive exposure to sun or UV light
Sohonos (palovarotene) can sometimes cause chapped lips, itching, rash, hair loss, and dry eye. It can also cause severe skin reactions, such as dry skin and skin peeling. These reactions raise your risk of skin infections and skin ulcers. If you experience any skin or allergic reactions, let your provider know. Your provider might lower your dose to help relieve these symptoms. Consider using lotion, lip balm, or artificial tears to help prevent or lower the risk of these reactions.
In addition, Sohonos (palovarotene) can cause you to sunburn more easily and severely. To lower your risk, make sure to limit or avoid sun exposure during treatment with this medication. Wear protective clothing, sunglasses, or sunscreen when outside, even on overcast days.
Bone problems
Risk factors: Weaker bones or bone-related conditions | Taking Sohonos (palovarotene) for a long time, especially at a high dose
Sohonos (palovarotene) can cause weakened bones, bone spurs (lumps that grow at the end of a bone), calcium buildups in your tendons or ligaments, and bone fractures. The risk is higher if you currently have bone problems or if you take Sohonos (palovarotene) for a long time, especially at a high dose. Your provider will monitor you for bone fractures regularly during treatment with this medication.
Depression and thoughts of self-harm
Risk factors: History of depression or other mental health condition
Sohonos (palovarotene) can cause depression, anxiety, aggressive behavior, and suicidal thoughts or behavior. Talk to your provider as soon as possible if you or anyone around you notice any unusual changes in your mood or behavior, especially during the first few months of treatment or when the dose changes.
Vision problems
Risk factors: Taking Sohonos (palovarotene) at a high dose
Sohonos (palovarotene) can worsen your vision at night. Be careful driving, especially at night, until you know how this medication affects you. If you notice changes in your vision, stop taking Sohonos (palovarotene) and talk to your provider right away.
Sohonos (palovarotene) dosage forms
Typical dosing for Sohonos (palovarotene)
Maintenance treatment
Adults and children 14 years and older: The typical dose is 5 mg by mouth daily with food.
Children ages 8 to 13 years old (females) or 10 to 13 years old (males): The dose will depend on your child’s weight. Dosage ranges from 2.5 mg to 5 mg daily.
Children weighing 10 kg to 19.9 kg: The typical dose is 2.5 mg by mouth daily with food.
Children weighing 20 kg to 39.9 kg: The typical dose is 3 mg by mouth daily with food.
Children weighing 40 kg to 59.9 kg: The typical dose is 4 mg by mouth daily with food.
Children weighing 60 kg and more: The typical dose is 5 mg by mouth daily with food.
Flare-up treatment
If your symptoms get worse and you experience a flare-up, your provider will raise your dose for a few months and give you a new schedule for taking the medication.
Your dose might differ if you take other medications or if you experience side effects from this medication.
How much does Sohonos (palovarotene) cost?
Sohonos (palovarotene) contraindications
Currently pregnancy
History of allergies to retinoids, such as isotretinoin and tretinoin
Sohonos (palovarotene) images
Get savings updates for Sohonos (palovarotene)
Receive price alerts, news, and other messages from GoodRx about Sohonos (palovarotene) and other healthcare topics and relevant savings offers.By signing up, I agree to GoodRx's Terms and Privacy Policy, and to receive marketing messages from GoodRx.
References
Best studies we foundIpsen Biopharmaceuticals, Inc. (2023). Sohonos- palovarotene capsule [package insert]. DailyMed.
Ipsen Biopharmaceuticals, Inc. (2023). US FDA approves Ipsen’s Sohonos™ (palovarotene) capsules, the first and only treatment for people with fibrodysplasia ossificans progressiva.
Ipsen Biopharmaceuticals, Inc. (2024). FOP flare ups.
Katagiri, T., et al. (2016). Bone morphogenetic proteins. Cold Spring Harbor Perspectives in Biology.
MedlinePlus. (2022). Fibrodysplasia ossificans progressiva.
MedlinePlus. (2023). Vitamin A.
National Health Service. (2022). Osteophyte (bone spur).
National Organization for Rare Disorders. (2023). Fibrodysplasia ossificans progressiva.
Pignolo, R. J., et al. (2022). Reduction of new heterotopic ossification (HO) in the open-label, phase 3 move trial of palovarotene for fibrodysplasia ossificans progressiva (FOP). Journal of Bone and Mineral Research.
U.S. Food and Drug Administration. (2023). FDA approves first treatment for fibrodysplasia ossificans progressiva.
Browse medications
View AllResearch prescriptions and over-the-counter medications from A to Z, compare drug prices, and start saving.