Results from a Phase 1/2 trial in recessive dystrophic epidermolysis bullosa (RDEB) showed that gene therapy candidate EB-101 led to durable wound healing and improved quality of life, according to Abeona Therapeutics.
The updated findings on Abeona’s investigational skin graft cell therapy were recently presented at the American Society for Gene and Cell Therapy’s 21st Annual Meeting in Chicago.
Patients with RDEB have mutations in the COL7A1 gene, which leads to a lack of functional type VII collagen (C7) in the skin. Collagen C7 is a major component of so-called anchoring fibrils, which are large structures that hold the skin together.
EB-101 was engineered to specifically deliver the correct form of the COL7A1 gene to patients using their own skin cells. This approach could lead to the production of the missing collagen C7 protein and help heal damaged skin.
The completed Phase 1/2 trial (NCT01263379) was conducted in collaboration with scientists at Stanford University and included seven patients. The first patient was treated over three years ago and still shows wound healing.
In the study, the therapeutic potential of EB-101 in nonhealing chronic wounds was assessed at predefined points in time. The therapy’s safety, tolerability, and preliminary effectiveness were compared with untreated wounds from a natural history study with 128 patients who had nearly 1,500 chronic and recurring RDEB wounds.
All 42 treated wounds on the seven patients healed at three months (wound healing was defined as more than 50 percent wound closure). Additionally, 38 of 42 (90 percent) were healed at six months; 24 of 36 (67 percent) on six subjects were healed at 12 months; 21 of 24 (88 percent) on four patients were healed at 24 months; and all six wounds on one patient were healed at 36 months post-treatment.
According to patient-recorded outcomes, the wound healing benefits of EB-101 were associated with significant reductions in pain and itch.
As for the supporting natural history study, 13 RDEB patients with a total of 15 chronic wounds received treatment with an allograft (transplant from one person to another), including Apligraf and Dermagraft, both from Organogenesis.
In this group, only one in 15 wounds (7 percent) remained healed at 12 weeks, while no wound was healed at 24 weeks.
The scientists noted the importance of this finding, as there are no RDEB therapies with lasting wound-closing effectiveness beyond two months of treatment.
The team also evaluated the production of collagen C7 and the restoration of anchoring fibrils at three and six months post-treatment, respectively. C7 and normal anchoring fibrils were observed as early as one month and remained for at least three years after treatment with EB-101.
“RDEB patients suffer throughout their lives from intense pain, life-threatening complications, and face a shortened life expectancy. Currently, there are no effective treatments available to reduce the severity of their symptoms,” Carsten Thiel, PhD, Abeona’s CEO, said in a press release. “The advancements made through this trial are clinically meaningful, showing significant and durable wound healing results and improved quality of life in these patients.”
Thiel also noted that Abeona is working with the U.S. Food and Drug Administration (FDA) to design a pivotal Phase 3 study to be started later this year.
The FDA granted EB-101 regenerative medicine advanced therapy designation for patients with dystrophic epidermolysis bullosa last January; breakthrough therapy designation in August 2017; and rare pediatric disease designation (including RDEB) and orphan drug designation in May 2017. The potential treatment also received orphan drug designation from the European Medicines Agency in March 2017.