FDA Approves Abeona Gene Therapy for Rare, Hereditary Skin Disease Treatment
Patients with the most severe hereditary disease suffer from skin, are susceptible to injury, and some never fully heal. The only treatment for years has been supportive care, including the laborious and frequent changes in wound dressings covering most of the body. Biotechnological studies of this disease, epidermal dissolving Bullosa (EB) have been adopted for therapeutic options. Now, the FDA has approved Abeona Therapeutics’ personalized treatments obtained from patients’ own skin cells, the third endorsement of the rare disease in the past two years.
The regulatory decision announced Tuesday that wounds in adults and children suffering from hidden malnutrition epidermal solution (RDEB). The therapy will be sold under the brand Zevaskyn, known in development as Prademagene Zamikeracel or Short PZ-Cel. Cleveland-based Abeona expects Zevaskyn to go public in the third quarter of this year.
“We hear from the RDEB community that meaningfully heals the persistence of RDEB wounds, unmet people, especially those that are chronic and prone to infection,” CEO Vishwas Seshdari said on a conference call Tuesday morning. “With one application, Zevaskyn can provide people with the opportunity to RDEB, which can alleviate wound closure and relieve pain even in the worst wounds.”
Epidermal dissolution Bulosa is caused by mutations in the Col7a1 gene, which encodes type VII collagen, which forms the anchoring protein connecting the dermis and the epidermis. Without these anchoring proteins, the skin will be susceptible to foam and wounds. Those with EB are sometimes called “butterfly children” because their skin is as thin and fragile as the wings of butterflies. In RDEB, the most severe form of EB, both copies of the Col7a1 gene were mutated.
Cell therapy was initially reached the market as a highly personalized cancer treatment, which was performed by engineering the patient's immune cells. Similar to these autologous therapies, patients are the starting point for Zevaskyn. Madhav Vasanthavada said skin cells that were biopsy from patients were genetically designed to express functional collagen. During the 25-day manufacturing process at the Abeona Cleveland plant, cells grew into credit card-sized bed sheets. A biopsy can produce up to 12 bed sheets. The shelf life of the manufactured sheets is 84 hours and are transported to a qualified treatment center for surgical application to the patient.
Zevaskyn was evaluated in a Phase 3 clinical trial, which recruited 11 patients with chronic wounds that lasted for 6.2 years and in some cases opened for up to 21 years. For each patient, a large wound (approximately 20 square feet in size) was treated with Zevaskyn and compared with the patient's untreated wound comparable in size. The main goal is to measure wound healing and pain within six months. The therapy achieves these goals. Follow-up for up to eight years, Abeona reported that patients continue to show durable wound healing and pain relief.
In terms of safety and tolerance, the most common adverse reactions reported in the study were procedural pain and itching. However, one of the risks of any therapy performed by genetic engineering is insertion of tumorigenesis, insertion of genes that may cause cancer or nearby gene payloads. So far, there have been no treatment complications, including any cancer cases, Seshdari said.
About a year ago, the FDA rejected Abeona's submission to Zevaskyn, citing more information about treatment manufacturing. Last November, the FDA accepted Abeona's resubmission and set a target date for April 29, 2025 for regulatory decisions.
Abeona estimates that there are about 1,500 patients in the United States who meet Zevaskyn. Patients will receive treatment in qualified hospitals who already have experience in patients with EB. Vasanthavada said Abeona's goal is to activate five of these locations in the third quarter of this year. By the end of 2025, 10 to 14 patients from the Vasanthavada program will be treated.
Zevaskyn's wholesale price is $3.1 million, and Vasanthavada says the therapy brings value to patients and the healthcare system. He said chronic wounds that need to be cared for in a RDEB patient are $1 million a year higher. Abeona will provide results-based protocols where a percentage of Zevaskyn's cost will be kicked back if the patient needs to treat a previously treated wound within three years. Vasanthavada said the initial payer feedback was encouraging, but he refused to provide more details due to ongoing discussions.
The FDA approved the first malnutrition EB therapy in 2023, a gene therapy from Krystal Biotech that applies to topical gels on the skin once a week. This therapy Vyjuvek provides skin cells with a functional version of the Col7a1 gene to promote normal collagen production. Krystal reported $250.5 million in sales for Vyjuvek in 2024.
The FDA also approved Chiesi Group's FILSUVEZ, a topical gel in 2023, with its main pharmaceutical ingredients designed to promote wound healing in patients with malnutrition EB and combined EB. Vasanthavada said there is a possibility that Zevaskyn will be used with other EB therapies. Payers recognize unmet needs and so far they have not said patients can only receive one treatment.
“It seems like a supplementary approach seems to work,” Vasanthavada said.
Abeona's engineering epidermis technology technology has been licensed by Stanford University, which will receive regulatory approval of milestone payments and royalties for Zevaskyn sales. As of the end of 2024, Abeona reported its cash position of $98.1 million.
The FDA approved Zevaskyn with a priority review credential that could be used to speed up regulatory approval for another treatment for rare pediatric diseases. However, companies that companies grant coupons are usually sold as non-second-tier ways to raise funds. Seshdari said Abeona plans to sell its vouchers to earn $150 million for its recent coupon sale.
Image by Abeona Therapeutics
