The US Food and Drug Administration (FDA) has approved Abeona Therapeutics’ Zevaskyn (prademagene zamikeracel) for use in recessive dystrophic epidermolysis bullosa (RDEB).

The decision makes Zevaskyn the first autologous cell-based gene therapy approved in the US to treat wounds in adult and paediatric patients with the rare skin disorder.

RDEB is an incurable connective tissue disease that causes the skin to become very fragile. It is characterised by extensive blistering and severe wounds that often cover more than 30% of a patient’s body surface.

Zevaskyn consists of a patient’s own skin cells that are genetically modified to produce functional type VII collagen, which RDEB patients are unable to produce due to a defect in both copies of the COL7A1 gene.

The therapy is surgically applied to a patient’s wounded areas in the form of a sheet and is expected to be available in the US from the third quarter of this year.

Abeona’s chief executive officer, Vish Seshadri, said the approval represents a “pivotal moment in the treatment of RDEB”.

“Through a single surgical application, Zevaskyn can now offer people with RDEB the opportunity for wound healing and pain reduction in even the most severe wounds,” Seshadri said.

The FDA’s approval was supported by results from the phase 3 VIITAL study, which demonstrated significant wound healing and pain reduction after a single treatment with Zevaskyn.

In the trial, 81% of the 43 large and chronic wounds treated with a single application of Abeona’s therapy showed 50% or more healing at six months, compared to 16% in 43 matched control wounds treated with standard of care.

A phase 1/2a study in 38 chronic wounds across seven patients also showed that a single application of Zevaskyn was associated with long-term improvement at treated sites over a median follow-up of 6.9 years.