Abeona Therapeutics has announced that the FDA has accepted the resubmission of its Biologics License Application (BLA) for prademagene zamikeracel (pz-cel) for the treatment of recessive dystrophic epidermolysis bullosa (RDEB). The FDA has assigned a Prescription Drug User Fee Act (PDUFA) target action date of April 29, 2025.
Pz-cel is an investigational autologous, COL7A1 gene-corrected epidermal sheet therapy. It is manufactured using a patient's own skin cells, which are genetically modified with a functional COL7A1 gene. These modified cells are then expanded into keratinocyte sheets designed to cover wound areas after a single surgical application. The therapy has been granted Regenerative Medicine Advanced Therapy, Breakthrough Therapy, Orphan Drug, and Rare Pediatric Disease designations by the FDA.
Addressing Unmet Needs in RDEB Treatment
"The FDA acceptance of our BLA resubmission moves us one step closer to providing pz-cel as a differentiated treatment option to address the persistent unmet needs of people with RDEB in the US," said Vish Seshadri, CEO of Abeona.
The original BLA submission for pz-cel received a complete response letter (CRL) from the FDA in April 2024. The FDA requested additional information related to validation requirements for certain manufacturing and release testing methods. Notably, the agency did not raise any concerns regarding the efficacy or safety data of pz-cel, nor did it request additional clinical trials or data.
Abeona held a Type A meeting with the FDA in August to align on the content of the BLA resubmission. The company believes the resubmission package addresses all chemistry, manufacturing, and controls items identified in the CRL, including observations from a pre-license inspection conducted in March 2024.
Clinical Data Supporting Pz-cel
The BLA for pz-cel is supported by data from the phase 3 VIITAL study (NCT04227106) and a phase 1/2 a study (NCT01263379) with up to 8 years of follow-up. The VIITAL study evaluated the efficacy, safety, and tolerability of pz-cel in 11 patients aged 6 years or older with RDEB. The study included 43 large chronic wound pairs, each measuring greater than 20 cm2 of surface area and open for a minimum of 6 months and a maximum of 21 years.
Pz-cel met both primary study endpoints: the proportion of RDEB wound sites with greater than or equal to 50% healing from baseline, and pain reduction associated with wound dressing change. The therapy was also well tolerated, with no serious treatment-related adverse events reported.
Understanding Recessive Dystrophic Epidermolysis Bullosa
RDEB is an inherited genetic disorder characterized by recurrent and chronic open wounds. The estimated incidence is 3.05 cases per 1 million live births, although some research suggests it could be as high as 95 per 1 million births. Common symptoms and complications include lesions and blistering, nail dystrophy and loss, infections, musculoskeletal contractures, ocular manifestations, and dental caries.
