A Study of FCX-007 for Recessive Dystrophic Epidermolysis Bullosa

DEFI-RDEB is a multi-center, intra-patient randomized, controlled, open-label, Phase 3 study of FCX-007 for the treatment of persistent non-healing and recurrent RDEB wounds in approximately 24 subjects. Each subject will serve as his/her own control. Each subject's target wounds will be paired then randomized to receive FCX-007 (treatment wound) or remain untreated (control wound). Up to three target wound pairs will be identified for each subject.

Subjects will receive intradermal injections of FCX-007 in each specified treatment wound in two or more treatment sessions. The first treatment session occurs at Day 1 and the second at Week 12/Month 3. Additional treatment sessions may occur at Week 24/Month 6 and Week 36/Month 9 when unclosed treatment wounds may be re-treated, and unclosed control wounds may be treated. Safety and efficacy assessments will occur at scheduled intervals through Week 48/Month 12, when the treatment period is completed, and a long-term safety follow-up period (through 15 years) commences for subjects who have received one or more FCX-007 injections.

Key Inclusion Criteria:

• Male or female ≥2 years of age at the Screening visit.
• Clinical diagnosis of RDEB with confirmation of COL7A1 genetic mutation.

Key Exclusion Criteria:

• Medical instability limiting ability to travel to the investigative site.
• Active infection with human immunodeficiency virus, hepatitis B or hepatitis C.
• The presence of COL7 antibodies.
• Evidence of systemic infection.
• Evidence or history of squamous cell carcinoma at the site to be injected.
• Evidence of or history of metastatic squamous cell carcinoma.
• Known allergy to any of the constituents of the product.
• Female who is pregnant or breastfeeding.
• Receipt of a chemical or biological intervention for the specific treatment of RDEB in the past three (3) months prior to screening or anticipated/planned during the screening and treatment period for this study.