Frank Vinluan , 2025-04-29 19:29:00
Patients who have the most severe form of a certain inherited disease have skin that is susceptible to wounds, some that never fully heal. For years, the only treatment was supportive care, including laborious and frequent changes of wound dressings covering much of the body. Biotechnology research in this disease, epidermolysis bullosa (EB), has pursued therapeutic options. A personalized treatment that Abeona Therapeutics makes from a patient’s own skin cells is now approved by the FDA, marking the agency’s third approval in this rare disorder in the past two years.
The regulatory decision announced Tuesday covers the treatment of wounds in adults and children who have recessive dystrophic epidermolysis bullosa (RDEB). The therapy, known in development as prademagene zamikeracel, or pz-cel for short, will be marketed under the brand name Zevaskyn. Cleveland-based Abeona expects Zevaskyn will become available in the third quarter of this year.
“We have heard from the RDEB community that there is a persistent, unmet need to meaningfully heal RDEB wounds, especially those that are chronic and prone to infection,” CEO Vishwas Seshdari said during a Tuesday morning conference call. “Through a single application, Zevaskyn can provide people with RDEB the opportunity for significant wound closure and pain reduction in even the most severe wounds.”
Epidermolysis bullosa is caused by mutations to the COL7A1 gene, which codes for type VII collagen that makes up the anchoring proteins connecting the dermis and the epidermis. Without these anchoring proteins, skin is susceptible to blisters and wounds. Those born with EB are sometimes called “butterfly children” because their skin is as thin and fragile as a butterfly’s wings. In RDEB, the most severe form of EB, both copies of the COL7A1 gene are mutated.
Cell therapy first reached the market as highly personalized cancer treatments made by engineering a patient’s immune cells. Similar to these autologous therapies, the patient is the starting point for Zevaskyn. Skin cells biopsied from a patient are genetically engineered to express functional collagen, Chief Commercial Officer and Head of Business Development Madhav Vasanthavada said. In a 25-day manufacturing process at Abeona’s Cleveland facility, cells are grown into sheets about the size of a credit card. A single biopsy yields up to 12 sheets. The manufactured sheets, which have a shelf life of 84 hours, are delivered to a qualified treatment center for surgical application to the patient.
Zevaskyn was evaluated in a Phase 3 clinical trial that enrolled 11 patients with large chronic wounds that had remained open for 6.2 years and in some cases were open for as long as 21 years. For each patient, a large wound (about 20 square centimeters in size) was treated with Zevaskyn and compared to a patient’s untreated wound site of comparable size. The main goal was to measure wound healing and pain at six months. The therapy met those goals. With up to eight years of follow-up, Abeona has reported patients continue to show durable wound healing and pain reduction.
As far as safety and tolerability, the most common adverse reactions reported in the studies were procedural pain and itching. But one of the risks of any therapy made by genetically engineering a cell is insertional oncogenesis, insertion of the genetic payload in or near a gene that can cause cancer. Seshdari said there have been no treatment related complications so far, including any cases of cancer.
About a year ago, the FDA turned down Abeona’s submission for Zevaskyn, citing the need for more information about the manufacturing of the therapy. Last November, the FDA accepted Abeona’s resubmission and set an April 29, 2025 target date for a regulatory decision.
Abeona estimates that there about 1,500 U.S. patients eligible for Zevaskyn. Patients will be treated at qualified hospitals that already have experience with EB patients. Vasanthavada said Abeona aims to activate five of these sites by the third quarter of this year. By the end of 2025, Vasanthavada projects 10 to 14 patients will have received the treatment.
Zevaskyn’s wholesale price is $3.1 million, which Vasanthavada said takes into account the value the therapy brings to patients and the healthcare system. Care for the chronic wounds of a single RDEB patient can be as high $1 million annually, he said. Abeona will offer outcomes-based agreements in which a percentage of Zevaskyn’s cost will be rebated if a patient requires treatment of a previously treated wound within three years. Vasanthavada said initial payer feedback has been encouraging, but he declined to provide more detail due to the ongoing discussions.
The FDA approved the first dystrophic EB therapy in 2023, a gene therapy from Krystal Biotech formulated as a topical gel applied to the skin once weekly. This therapy, Vyjuvek, delivers to skin cells a functioning version of the COL7A1 gene to promote normal collagen production. Krystal reported $250.5 million in sales for Vyjuvek in 2024.
The FDA in 2023 also approved Chiesi Group’s Filsuvez, a topical gel whose main pharmaceutical ingredient is intended to promote wound healing in patients with dystrophic EB and junctional EB. Vasanthavada said it’s possible for Zevaskyn to be used alongside other EB therapies. Payers recognize the unmet need, and in discussions so far they have not said that patients can only have one therapy.
“It looks like a complementary approach seems viable,” Vasanthavada said.
Abeona’s technology for engineering epidermal sheets was licensed from Stanford University, which is in line to receive a regulatory approval milestone payment as well as royalties from Zevaskyn sales. As of the end of 2024, Abeona reported its cash position was $98.1 million.
FDA approval of Zevaskyn came with a priority review voucher that may be used to speed up regulatory approval of another therapy for a rare pediatric disease. But companies awarded vouchers typically sell them as a non-dilutive way to raise money. Seshdari said Abeona plans to sell its voucher, aiming for the $150 million that recent voucher sales have fetched.
Photo by Abeona Therapeutics
