Clinical trials are greatly beneficial in understanding more about therapeutics and various conditions. For example, the Phase 3 VIITAL trial will evaluate the safety, efficacy, and tolerability of EB-101, an investigational therapy for those with recessive dystrophic epidermolysis bullosa (RDEB). On March 14, 2022, biopharmaceutical company Abeona Therapeutics Inc. (“Abeona”) shared that the VIITAL study had reached target enrollment.

Dystrophic Epidermolysis Bullosa (DEB): An Overview

Before we dive deeper into EB-101 and the VIITAL trial, let’s first take a look at what recessive dystrophic epidermolysis bullosa (RDEB) is. Dystrophic epidermolysis bullosa (DEB) falls under the greater umbrella of of epidermolysis bullosa, rare genetic conditions which cause fragile and easily blistered skin. DEB has multiple subtypes, including dominant (DDEB), recessive dystrophic epidermolysis bullosa severe generalized (RDEB-sev gen), and RDEB generalized and localized (RDEB-gen -loc). COL7A1 gene mutations, which affect Type VII collagen in the body, cause DEB. Those with DDEB inherit the condition in an autosomal dominant fashion (requiring only one mutated gene) while RDEB is inherited in an autosomal recessive pattern (requiring two defective genes).

Symptoms and severity vary based on subtype. For example, those with DDEB have mild-to-moderate scarring, blistering on the hands, knees, elbows, and feet, and malformed or missing fingers and toenails. Next, those with RDEB generalized or localized have blistering on the same body parts, alongside malformed fingernails and scarring. Those with RDEB-sev gen have the most severe symptoms. These patients are often born with blistered or missing skin. Unlike those with other subtypes, blistering is more widespread. Blisters can be found all over the body, including in the mucous membranes, and may cause more severe scarring. RDEB-sev gen may also present with slowed growth, feeding difficulties, contractors, fused skin between the fingers and toes, missing fingernails and toenails, and ocular inflammation.

Evaluating EB-101

RDEB can also cause delayed wound healing, severe wounds, and severe pain. However, there are no FDA-approved treatments for patients. As a result, there is some urgency behind this research – a genuine desire to ensure that those with RDEB are able to receive therapies which reduce pain, spur healing, and improve quality-of-life. Earlier findings from a Phase 1/2a trial highlighted how EB-101 improved wound healing and pain for up to six years following treatment.

Abeona describes EB-101 as an autologous cell therapy. Using gene transferring, Abeona delivers functional COL7A1 into skin cells called keratinocytes that are sourced directly from patients. Next, these cells are transplanted back to patients. The hope is that this will allow patients to begin creating and expressing adequate type VIII collagen to ensure skin health and improved wound healing. EB-101 has earned Orphan Drug, Regenerative Medicine Advanced Therapy, Rare Pediatric Disease, and Breakthrough Therapy designations within the United States. The EMA (in Europe) also granted EB-101 Orphan Drug status.

Within the Phase 3 VIITAL trial, researchers are evaluating EB-101 for RDEB. Those within the study have wounds which have not healed in 6~ months and are larger than 20 cm-squared in surface area. The target enrollment goal was 10 individuals and 36 wound pairs (treated vs. untreated). Researchers hope to learn how well EB-101 improves wound healing and pain within a 24-week period. More data should be available by the end of the year.