A systematic literature review of the disease burden in patients with recessive dystrophic epidermolysis bullosa.

BACKGROUND/OBJECTIVE: Recessive dystrophic epidermolysis bullosa (RDEB) is a genetic collagen disorder characterized by skin fragility leading to blistering, wounds, and scarring. There are currently no approved curative therapies. The objective of this manuscript is to provide a comprehensive literature review of the disease burden caused by RDEB. METHODS: A systematic literature review was conducted in MEDLINE and Embase in accordance with PRISMA guidelines. Observational and interventional studies on the economic, clinical, or humanistic burden of RDEB were included. RESULTS: Sixty-five studies were included in the review. Patients had considerable wound burden, with 60% reporting wounds covering more than 30% of their body. Increases in pain and itch were seen with larger wound size. Chronic wounds were larger and more painful than recurrent wounds. Commonly reported symptoms and complications included lesions and blistering, anemia, nail dystrophy and loss, milia, infections, musculoskeletal contractures, strictures or stenoses, constipation, malnutrition/nutritional problems, pseudosyndactyly, ocular manifestations, and dental caries. Many patients underwent esophageal dilation (29-74%; median dilations, 2-6) and gastrostomy tube placement (8-58%). In the severely affected population, risk of squamous cell carcinoma (SCC) was 76% and mortality from SCC reached 84% by age 40. Patients with RDEB experienced worsened quality of life (QOL), decreased functioning and social activities, and increased pain and itch when compared to other EB subtypes, other skin diseases, and the general population. Families of patients reported experiencing high rates of burden including financial burden (50-54%) and negative impact on private life (79%). Direct medical costs were high, though reported in few studies; annual payer-borne total medical costs in Ireland were $84,534 and annual patient-borne medical costs in Korea were $7392. Estimated annual US costs for wound dressings ranged from $4000 to $245,000. Patients spent considerable time changing dressings: often daily (13-54% of patients) with up to three hours per change (15-40%). CONCLUSION: Patients with RDEB and their families/caregivers experience significant economic, humanistic, and clinical burden. Further research is needed to better understand the costs of disease, how the burden of disease changes over the patient lifetime and to better characterize QOL impact, and how RDEB compares with other chronic, debilitating disorders.

Screening Clinical Cell Products for Replication Competent Retrovirus: The National Gene Vector Biorepository Experience.

Replication-competent retrovirus (RCR) is a safety concern for individuals treated with retroviral gene therapy. RCR detection assays are used to detect RCR in manufactured vector, transduced cell products infused into research subjects, and in the research subjects after treatment. In this study, we reviewed 286 control (n = 4) and transduced cell products (n = 282) screened for RCR in the National Gene Vector Biorepository. The transduced cell samples were submitted from 14 clinical trials. All vector products were previously shown to be negative for RCR prior to use in cell transduction. After transduction, all 282 transduced cell products were negative for RCR. In addition, 241 of the clinical trial participants were also screened for RCR by analyzing peripheral blood at least 1 month after infusion, all of which were also negative for evidence of RCR infection. The majority of vector products used in the clinical trials were generated in the PG13 packaging cell line. The findings suggest that screening of the retroviral vector product generated in PG13 cell line may be sufficient and that further screening of transduced cells does not provide added value.

An investigator-initiated open-label clinical trial of vismodegib as a neoadjuvant to surgery for high-risk basal cell carcinoma.

BACKGROUND: Vismodegib is an oral hedgehog-pathway inhibitor approved for advanced basal cell carcinoma (BCC). Although most BCCs are amenable to surgery, excision of large tumors in aesthetically sensitive sites may compromise function or cosmesis. OBJECTIVE: We sought to evaluate the reduction in BCC surgical defect area after 3 to 6 months of neoadjuvant vismodegib. METHODS: This was an open-label, single-arm intervention trial with a primary outcome of change in target-tumor surgical defect area pre- and post-vismodegib (150 mg/d). Secondary outcomes were change in tumor area and tolerability. RESULTS: Eleven of 15 enrolled patients, aged 39 to 100 years, completed the trial. Thirteen target tumors were excised after a mean of 4±2 months of vismodegib. In all, 29% (4 of 14 patients) could not complete more than 3 months because of vismodegib-related side effects. The mean baseline target-tumor diameter was 3.2 cm, and 10 of 13 tumors occurred on the face. Overall, vismodegib reduced the surgical defect area by 27% (95% confidence interval -45.7% to -7.9%; P=.006) from baseline. Vismodegib was not effective in patients who received less than 3 months. Over a mean follow-up of 11.5 (range 4-21) months for all tumors, only 1 tumor recurred at 17 months post-Mohs micrographic surgery. LIMITATIONS: Short follow-up time and no placebo control are limitations. CONCLUSION: Neoadjuvant vismodegib appears to reduce surgical defect area when taken for 3 months or longer for nonrecurrent BCCs in functionally sensitive locations. Further studies with larger sample sizes and long-term follow-up are warranted.