Filsuvez (birch triterpenes)
An approved treatment for Epidermolysis Bullosa.
The same compound appears under different names depending on the context. Here is how to identify Birch triterpenes wherever you encounter it, plus the key facts at a glance.
- Generic name
- Birch triterpenes
- Brand name
- Filsuvez
- Development code
- Oleogel-S10
- Drug class
- Botanical topical gel (birch bark extract)
- Manufacturer
- Chiesi (developed by Amryt Pharmaceuticals, now part of Chiesi)
- How it's taken
- Wash hands or wear gloves, then spread a layer about 1 mm thick over the cleaned wound surface only, without rubbing it in, and cover with a sterile non-stick dressing.
A birch bark gel spread on wounds at each dressing change, approved by the FDA on December 18, 2023 for wounds from dystrophic and junctional epidermolysis bullosa in people 6 months and older. In its main trial, 41.3% of patients had their chosen wound close completely within 45 days, against 28.9% with a placebo gel.
Where Birch triterpenes fits
A gel that fits into routine dressing changes rather than a gene therapy. It is the only one of the 3 FDA-approved EB wound treatments that covers junctional EB, and Chiesi describes it as the first approved treatment for junctional EB wounds.
How Birch triterpenes works
Filsuvez is a botanical drug. Its active ingredient is a dry extract of bark from birch trees (Betula pendula and Betula pubescens), made up of natural compounds called triterpenes, mostly betulin (72% to 88%) with smaller amounts of lupeol, betulinic acid, erythrodiol and oleanolic acid. The extract is mixed into refined sunflower oil as a 10% gel with no other ingredients. The label states that how it works in EB wounds is unknown. Very little reaches the bloodstream: in the main trial, betulin levels were too low to measure in 68% of patients tested after 90 days.
Mechanism: Topical gel of refined birch bark extract (mostly betulin) in sunflower oil; how it helps EB wounds heal is not known
Side effects and safety
- Allergic and skin reactions. Hives and dermatitis have been reported. Stop Filsuvez right away and call your doctor if signs of an allergic or skin reaction appear.
- Infected wounds. If a treated wound becomes infected, stop applying Filsuvez to that wound until the infection has cleared.
- Eyes and mucous membranes. For skin wounds only. Keep it out of the eyes, mouth, vagina and anus, and rinse with water after accidental contact.
- No routine lab monitoring is listed in the label
- Watch treated wounds for signs of infection, such as redness, warmth, swelling, pain or pus
Filsuvez has no boxed warning and no contraindications. In the 90-day blinded part of the main trial, the only side effect reported in at least 2% of patients and more often than with placebo gel was application site reactions such as itching and pain (7.3% against 6.1%). The label warns about allergic and skin reactions, including hives and dermatitis, and says to stop using it right away if they appear. If a treated wound becomes infected, stop applying it to that wound until the infection clears. Squamous cell carcinoma of the skin was reported in 4 trial participants with recessive dystrophic EB, 1 on the first day of the trial and 3 during the open-label phase; 2 of the 4 had applied Filsuvez to the area where the cancer developed[1]. This type of skin cancer is a known high risk in severe EB[4].
This is not a complete list of side effects. Talk to your doctor or pharmacist about what to expect and when to seek medical attention.
Taking Birch triterpenes
Wash hands or wear gloves, then spread a layer about 1 mm thick over the cleaned wound surface only, without rubbing it in, and cover with a sterile non-stick dressing. It can also be spread directly onto the dressing so the gel touches the wound. It is applied at each dressing change, every 1 to 4 days in the main trial, until the wound heals. Each tube holds 23.4 g of gel and is for one use only: once opened it should be used right away and any leftover gel thrown away. It is for skin use only and should not go in the eyes or on mucous membranes. Store at room temperature, 20 to 25°C, and do not freeze[1].
Availability and cost
Only available as the brand-name product.
Help paying for Filsuvez
Pick your insurance to see which help fits. Drugmaker copay cards can't be used with Medicare, Medicaid or TRICARE; charity funds are the usual route there.
- Copay help
FILSUVEZ Copay Program: eligible commercially insured patients may pay as little as $0 for their prescription. Patients must enroll in Chiesi Total Care and live in the US or its territories. Government-funded plans are not eligible.
For: private insurance · source - Insurance and case manager help
Patient service coordinators help with insurance benefits and financial assistance options; nursing support and wound care education; refills with 24-hour pharmacist availability and home delivery.
The official page does not say who qualifies. Ask the program. · source
Good to know: The copay terms printed on the Filsuvez page carry a Ferriprox heading and a $10,000 yearly cap, so the cap was left out because it is unclear whether it applies to Filsuvez. The page says financial assistance options exist for government-insured and uninsured patients but gives no details. Hours Monday to Friday 8 AM to 8 PM ET.
- From a charity · The Assistance FundEpidermolysis Bullosa (EB) fundOpen
Pays for: Copays, coinsurance, deductibles and other health-related expenses.
The foundation says: “OPEN — Accepting New Patients. TAF is currently accepting new patient enrollments for this program.”
Access and eligibility
Approved for wounds from dystrophic or junctional EB in adults and children 6 months and older. It is not approved for EB simplex or for babies younger than 6 months. The main trial treated partial-thickness wounds of 10 to 50 square centimeters that had been open for 21 days to 9 months.
Source: Chiesi Total Care for Filsuvez
Access program details are provided for informational purposes and may vary based on insurance coverage, geographic location, and individual circumstances. Confirm current eligibility directly with the manufacturer or your specialty pharmacy.
Clinical trial results
Approval rested on EASE (NCT03068780), which randomly assigned 223 people with inherited EB, aged 6 months to 81 years (70% under 18), to Filsuvez or a placebo gel on all wounds for 90 days. Most had dystrophic EB (175 recessive and 20 dominant), 26 had junctional EB and 2 had EB simplex. The main measure was first complete closure of a chosen partial-thickness wound within 45 days: 41.3% on Filsuvez against 28.9% on placebo gel. In recessive dystrophic EB the figures were 44.0% against 26.2%; in the smaller dominant dystrophic group the rate was 50.0% in both arms, and in junctional EB it was 18.2% against 26.7%. By day 90, 50.5% and 43.9% had closure, a difference that was not statistically significant[1][4][6]. The trial was published in the British Journal of Dermatology in 2023[5].
Development history
Amryt Pharmaceuticals developed the gel as Oleogel-S10 and submitted it to the FDA on March 30, 2021. The FDA did not approve it after its first review, issuing an action letter on February 26, 2022, and approved Filsuvez on December 18, 2023 after Amryt responded in October 2023[2][3]. Chiesi had acquired Amryt that year, and Chiesi Global Rare Diseases announced the approval on December 19, 2023, describing Filsuvez as the first approved treatment for wounds from junctional EB. The European Commission had approved it in June 2022[4].
Explore Epidermolysis Bullosa trials
Other Epidermolysis Bullosa treatments
EB has 3 FDA-approved wound treatments: Vyjuvek (beremagene geperpavec) since May 2023 for dystrophic EB, Filsuvez (birch triterpenes) gel since December 2023 for dystrophic and junctional EB wounds in people 6 months and older, and Zevaskyn (prademagene zamikeracel) since April 2025 for recessive dystrophic EB wounds. No trial has compared them with each other, and none is approved for EB simplex.
Common questions about Birch triterpenes
▸What is Birch triterpenes (Filsuvez)?
A birch bark gel spread on wounds at each dressing change, approved by the FDA on December 18, 2023 for wounds from dystrophic and junctional epidermolysis bullosa in people 6 months and older. In its main trial, 41.3% of patients had their chosen wound close completely within 45 days, against 28.9% with a placebo gel.
▸How does Birch triterpenes work?
Filsuvez is a botanical drug. Its active ingredient is a dry extract of bark from birch trees (Betula pendula and Betula pubescens), made up of natural compounds called triterpenes, mostly betulin (72% to 88%) with smaller amounts of lupeol, betulinic acid, erythrodiol and oleanolic acid. The extract is mixed into refined sunflower oil as a 10% gel with no other ingredients. The label states that how it works in EB wounds is unknown. Very little reaches the bloodstream: in the main trial, betulin levels were too low to measure in 68% of patients tested after 90 days.
▸What are the side effects of Birch triterpenes?
Filsuvez has no boxed warning and no contraindications. In the 90-day blinded part of the main trial, the only side effect reported in at least 2% of patients and more often than with placebo gel was application site reactions such as itching and pain (7.3% against 6.1%). The label warns about allergic and skin reactions, including hives and dermatitis, and says to stop using it right away if they appear. If a treated wound becomes infected, stop applying it to that wound until the infection clears. Squamous cell carcinoma of the skin was reported in 4 trial participants with recessive dystrophic EB, 1 on the first day of the trial and 3 during the open-label phase; 2 of the 4 had applied Filsuvez to the area where the cancer developed[1]. This type of skin cancer is a known high risk in severe EB[4].
▸How is Birch triterpenes taken?
Wash hands or wear gloves, then spread a layer about 1 mm thick over the cleaned wound surface only, without rubbing it in, and cover with a sterile non-stick dressing. It can also be spread directly onto the dressing so the gel touches the wound. It is applied at each dressing change, every 1 to 4 days in the main trial, until the wound heals. Each tube holds 23.4 g of gel and is for one use only: once opened it should be used right away and any leftover gel thrown away. It is for skin use only and should not go in the eyes or on mucous membranes. Store at room temperature, 20 to 25°C, and do not freeze[1].
▸Is Birch triterpenes FDA approved?
Yes, Birch triterpenes (Filsuvez) is FDA approved (2023) for the treatment of Epidermolysis Bullosa.
▸Is Filsuvez a gene therapy?
No. Filsuvez is a gel made from a refined birch bark extract in sunflower oil. It does not change genes, and the label says how it helps EB wounds is unknown. It is applied at routine dressing changes, while Vyjuvek and Zevaskyn are gene therapies.
▸Does Filsuvez work for junctional EB?
Filsuvez is approved for wounds from both dystrophic and junctional EB in people 6 months and older. In the EASE trial overall, 41.3% of patients on Filsuvez had their target wound close within 45 days against 28.9% on placebo gel. The junctional EB group was small, 26 patients, and its closure rate was 18.2% on Filsuvez against 26.7% on placebo gel, so ask your EB doctor what to expect.
▸How often do you apply Filsuvez?
At every dressing change until the wound heals. In the main trial, dressings were changed every 1 to 4 days. You spread a layer about 1 mm thick on the wound, or on the non-stick dressing, without rubbing it in, and use each tube only once.
Sources and references
Every factual claim on this page is drawn from the public sources listed below. Click any reference to open the original document.
- U.S. National Library of Medicine, DailyMed. FILSUVEZ (birch triterpenes) topical gel: prescribing information. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=32ba9194-734c-47d4-84e1-b21e28a85ec5
- U.S. Food and Drug Administration · 2023-12-18. NDA 215064 approval letter. https://www.accessdata.fda.gov/drugsatfda_docs/appletter/2023/215064Orig1s000ltr.pdf
- U.S. Food and Drug Administration. Novel Drug Approvals for 2023. https://www.fda.gov/drugs/novel-drug-approvals-fda/novel-drug-approvals-2023
- Chiesi Farmaceutici · 2023-12-19. Chiesi Global Rare Diseases Receives FDA Approval for FILSUVEZ (birch triterpenes) topical gel for the Treatment of Epidermolysis Bullosa. https://www.chiesi.com/en/media-hub/press-releases/global-rare-diseases-approval-filsuvezr
- British Journal of Dermatology · 2023. Efficacy and safety of Oleogel-S10 (birch triterpenes) for epidermolysis bullosa: results from the phase III randomized double-blind phase of the EASE study. https://doi.org/10.1093/bjd/ljac001
- ClinicalTrials.gov. Phase III Efficacy and Safety Study of Oleogel-S10 in Epidermolysis Bullosa (EASE). https://clinicaltrials.gov/study/NCT03068780
- Chiesi USA. Filsuvez support for patients and caregivers: Chiesi Total Care. https://chiesitotalcare.com/filsuvez/patients-caregivers/