Abeona Therapeutics has announced that the FDA has accepted the resubmission of its Biologics License Application (BLA) for prademagene zamikeracel (pz-cel), an investigational autologous, cell-based gene therapy for the treatment of recessive dystrophic epidermolysis bullosa (RDEB). The FDA has set a Prescription Drug User Fee Act (PDUFA) target action date of April 29, 2025.
Pz-cel is designed to address the underlying genetic defect in RDEB by delivering a functional copy of the COL7A1 gene to patients' skin cells. The therapy involves engineering a patient's own skin cells ex vivo to express the COL7A1 gene, expanding these cells into keratinocyte sheets, and then surgically applying these sheets to the patient's RDEB wounds.
Addressing Regulatory Hurdles
The BLA resubmission follows a Complete Response Letter (CRL) issued by the FDA in April 2024, which requested additional Chemistry, Manufacturing, and Controls (CMC) information. According to Abeona, the FDA did not raise any concerns regarding the clinical efficacy or safety data included in the original BLA and did not request any new clinical trials or data.
Vish Seshadri, Chief Executive Officer of Abeona, stated, "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. We look forward to continuing to work with the FDA to finalize the review of the pz-cel application."
Clinical Evidence andtrial data
The BLA is supported by data from the Phase 3 VIITAL study (NCT04227106) and a Phase 1/2a study (NCT01263379). Results from the VIITAL study, reported in November 2022, demonstrated that pz-cel significantly improved wound healing and reduced pain in patients with RDEB. The VIITAL study met its primary endpoints, showing over 50% wound healing and a greater magnitude of pain reduction at 6 months post-treatment compared to baseline and control wounds.
Principal investigator Jean Tang, MD, PhD, a professor of Dermatology at Stanford University School of Medicine, noted the impact of pz-cel on large, chronic RDEB wounds, stating, "In the phase 3 VIITAL study, EB-101 has been shown to both heal such large chronic wounds and significantly reduce pain. And we continue to see durable clinical benefit of EB-101 with up to 8 years of follow-up in our phase 1/2a study."
Market Context and Other RDEB Therapies
If approved, pz-cel would enter a market that already includes Krystal Biotech’s beremagene geperpavec (B-VEC), marketed as Vyjuvek, which was approved by the FDA in May 2023. Vyjuvek is a topically applied gene therapy that delivers functional copies of the COL7A1 gene to skin cells. Pz-cel differs in its approach by using autologous, gene-corrected epidermal sheets applied surgically.
Financial Position
Abeona Therapeutics reported having $110.0 million in cash, cash equivalents, short-term investments, and restricted cash as of September 30, 2024. The company estimates that these resources, along with its credit facility, will be sufficient to fund operations into 2026, before considering potential revenue from pz-cel sales or proceeds from a Priority Review Voucher (PRV), if awarded.
