Abeona Therapeutics, Inc. has announced updated clinical data from the ongoing Phase 1/2 clinical trial for the EB-101 gene therapy program for patients with Recessive Dystrophic Epidermolysis Bullosa (RDEB), a severe form of epidermolysis bullosa (EB), along with supportive natural history data for 128 patients with the fatal skin disease. These data were presented at the Society for Investigative Dermatology (SID) conference by Abeona’s scientific and clinical collaborators at Stanford University School of Medicine, a center of excellence for the treatment of patients with epidermolysis bullosa.  

“Last week at the SID conference, our EB-101 team of clinical investigators and scientific collaborators presented data from the ongoing Phase 1/2 gene therapy clinical trial and a supportive natural history study of patients with RDEB that highlight the unprecedented wound healing and durable collagen C7 expression of four patients through two years post-treatment, including one patient that has continued to see EB-101 treated wounds remain healed three years post-treatment. The relevance of these benefits is highlighted when compared to non-treated control wounds evaluated from the 128-patient natural history study, which showed that RBEB patients suffer chronic and recurrent wounds that do not heal on their own and persist for several years,” said Timothy J. Miller, Ph.D., President and CEO.

In the Phase 1/2 trial, EB-101 was administered to non-healing chronic wounds [mean length of time wounds were unhealed (unclosed) was 8.5 years prior to the gene therapy administration] on each subject and assessed for wound healing at predefined time points over years. The primary endpoint of the clinical trial is to assess safety and evaluate wound closure after EB-101 administration compared to control untreated wounds. Secondary endpoints include expression of full-length collagen C7 and restoration of anchoring fibrils at three and six months post-administration.  

As reflected at the conference by Stanford collaborators, wounds were evaluated at three, six, 12, 24 and 36 months for appearance, durability, and resistance to blistering**:

Wound healing >50%:  defined as >50% closure after EB-101 administration was observed in:
- 100% (36/36 treated wounds, n=6 subjects) at 3 months;
- 89% (32/36 treated wounds, n=6 subjects) at 6 months;
- 83% (20/24 treated wounds, n=4 subjects) at 12 months,
- 88% (21/24 treated wounds, n=4 subjects) at 24 months,
- 100% (6/6 treated wounds, n=1 subject) at 36 months post-administration.

Wound healing >75%: defined as >75% closure after EB-101 administration was observed in:
- 83% (30/36 treated wounds, n=6 subjects) at 3 months;
- 61% (22/36 treated wounds, n=6 subjects) at 6 months;
- 50% (12/24 treated wounds, n=4 subjects) at 12 months;
- 71% (17/24 treated wounds, n=4 subjects) at 24 months;
- 83% (5/6 treated wounds, n=1 subject) at 36 months post-administration. 

Collagen VII (C7) expression observed: C7 and morphologically normal NC2 reactive anchoring fibrils – the “zipper” that holds skin onto the underlying tissue and the primary deficit in RDEB patients – have been observed in EB-101 treatments up to two years post administration.

Data from a supportive natural history study of 1,436 wounds of 128 patients with RDEB, established by Stanford and EBCare Registry, were also presented at the conference. The natural history study characterized both chronic non-healing wounds, defined as an area that does not heal ≥12 weeks, and recurrent wounds, defined as an area that partially heals but then easily re-blisters. Results presented were characterized as 1041 recurrent wounds and 395 chronic open wounds. Notably, in the natural history study, 13 RDEB patients with a total of 15 chronic wounds were treated with an allograft product, including Apligraf® and Dermagraft®***. Of these wounds treated with allografts, only 7% (1/15 treated wounds) remained healed after 12 weeks, and 0% (0/15 treated wounds) remained healed after 24 weeks. This is a meaningful finding of the natural history study, as there are no approved therapies for RDEB patients that demonstrate significant wound closure after two months post-application.