The purpose of this study is to determine whether administration of D-Fi in addition to standard of care improves wound healing as compared to standard of care alone (control) in children, adolescents, and adults with Dystrophic Epidermolysis Bullosa.

CCB-EB-304 is a multi-center, intra-patient randomized and controlled, open-label, rater-blinded Phase 3 study of D-Fi for the treatment of persistent non-healing and recurrent DEB wounds in approximately 32 subjects. Each subject will serve as his/her own control. Each subject's Target Wounds will be paired then randomized to receive D-Fi (Treatment Wound) or remain untreated (Control Wound). One Target Wound Pair will be identified for each subject.

Subjects will receive intradermal injections of D-Fi in each specified Treatment Wound in three or more treatment sessions. The first treatment session occurs at Day 1, the second at Week 8/Month 2 and the third at Week 16/Month 4. Additional treatment sessions may occur at Week 26/Month 6 and Week 32/Month 8 and Week 40/Month 10 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 is followed by an optional Open-Label Extension (OLE) treatment phase of an additional 96 weeks. A long-term safety follow-up period (through 15 years) commences for subjects who have received one or more D-Fi injections, either following the treatment phase or if the subject had opted-in, the OLE.

Inclusion Criteria:

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

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 clinically significant COL7 antibodies.
• Evidence of systemic infection.
• Known allergy to any of the constituents of the product.
• Female who is pregnant or breastfeeding.