Epidermolysis bullosa (EB) refers to a clinically heterogeneous group of blistering skin disorders that occurs with similar incidence across all populations in Europe and throughout the world (Fine et al. J Am Acad Dermatol 2008; 58: 931-50). One of the most clinically severe subtypes of EB is RDEB. This autosomal recessive condition is caused by loss-of-function mutations in the COL7A1 gene, which encodes the skin protein type VII collagen (C7) (Dang and Murrell Exp Dermatol 2008; 17: 553-68).
Loss of C7, which is expressed in the basement membrane at the junction between the epidermis and the dermis, leads to structural defects in adhesion structures known as anchoring fibrils. These changes make the skin fragile and susceptible to blistering following trauma. Blistering often leads to chronic erosions and there is poor wound healing of traumatised skin. In addition, the impaired healing can be followed by scarring and contractures, as well as several major cutaneous and systemic complications (Fine and Mellerio J Am Acad Dermatol 2009; 61: 367-84 and 387-402).
These complications include an increased risk of skin malignancy, anaemia, oesophageal stricture, nutritional deficiencies, constipation, ocular scarring, dental decay, endocrine abnormalities, and osteoporosis. RDEB also has a major impact on quality of life, social and family interactions (Frew et al. Br J Dermatol 2009; 161: 1323-30) At present, there is no effective treatment for RDEB; current best practice involves application of protective dressings (which can take several hours each day and which is often painful) and monitoring/attempting to treat disease complications. Nevertheless, several research groups around the world are trying to develop new therapies for RDEB. These attempts are based on developing gene, protein, cell and drug therapies.
To date, only cell therapy has entered the clinical arena. One of the first studies in this area has involved intradermal injections of fibroblasts in 5 subjects (Wong et al. J Invest Dermatol 2008; 128cells in 2 individuals (Conget et al. Cytotherapy 2010; 12: 429-31). Following on from this study, Intercytex has been collaborating with Professor John McGrath who led the team carrying out this work. The current experience of injecting ICX-RHY in 14 individuals with RDEB indicates that this therapy can deliver a disease-modifying intervention without the adverse events associated with topical application and should provide a major step forward in delivering translational research to benefit patients.