FDA Sets Review Date for Therapy for Rare Connective Tissue Disorder

The FDA has accepted and granted priority review for the biologics license application (BLA) for pz-cel (prademagene zamikeracel), Abeona Therapeutics’ therapy for patients with recessive dystrophic epidermolysis bullosa (RDEB), a rare connective tissue disorder. The disorder causes severe and painful skin wounds and can lead to systemic complications. People with RDEB have a defect in the COL7A1 gene, leaving them unable to produce functioning Type VII collagen.

Pz-cel is cell therapy designed to incorporate the functional collagen-producing COL7A1 gene into a patient’s own skin cells. The FDA has set a Prescription Drug User Fee Act (PDUFA) target action date of May 25, 2024. Regulators have said they don’t currently plan to convene an advisory committee meeting to discuss the pz-cel application.

Vishwas Seshadri, Ph.D.

“The FDA’s acceptance of our BLA for priority review underscores the high unmet need in RDEB and the potential for pz-cel to provide meaningful benefit to these patients,” Vishwas Seshadri, Ph.D., CEO of Abeona, said in a press release.

The BLA is supported by clinical efficacy and safety data from the pivotal phase 3 VIITAL study and confirmatory evidence from a phase 1/2a study. Both studies revealed that a one-time application of pz-cel on large and chronic wounds delivered sustained wound healing and pain reduction.

Data from the VIITAL study were presented during the inaugural International Societies for Investigative Dermatology (ISID) Meeting in May 2023. Long-term follow up data up to eight years and quality of life data from the phase 1/2a study were published in Orphanet Journal of Rare Diseases.

The VIITAL study is a randomized clinical trial that evaluated the efficacy, safety and tolerability of pz-cel in 43 large chronic wound pairs in 11 patients with RDEB. Both co-primary endpoints of VIITAL were met, with 81% of pz-cel–treated wounds demonstrating ≥50% healing and a greater reduction in pain severity observed in pz-cel−treated wounds compared with control wounds.

There were no reports of patient-level or wound-specific serious treatment related adverse events and only a small number of nonserious treatment related adverse events.

In the phase 1/2a study, at year five, 70% of the 30 treated sites demonstrated ≥ 50% wound healing compared with baseline by investigator global assessment. Grafts were well-tolerated throughout long-term follow-up. No serious adverse events related to treatment were reported over a mean of 5.9 years of follow-up.