Safety and early efficacy outcomes for lentiviral fibroblast gene therapy in recessive dystrophic epidermolysis bullosa
Su M. Lwin, et al.
Su M. Lwin, et al.
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Clinical Research and Public Health Dermatology Genetics

Safety and early efficacy outcomes for lentiviral fibroblast gene therapy in recessive dystrophic epidermolysis bullosa

Abstract

BACKGROUND Recessive dystrophic epidermolysis bullosa (RDEB) is a severe form of skin fragility disorder due to mutations in COL7A1 encoding basement membrane type VII collagen (C7), the main constituent of anchoring fibrils (AFs) in skin. We developed a self-inactivating lentiviral platform encoding a codon-optimized COL7A1 cDNA under the control of a human phosphoglycerate kinase promoter for phase I evaluation.METHODS In this single-center, open-label phase I trial, 4 adults with RDEB each received 3 intradermal injections (~1 × 106 cells/cm2 of intact skin) of COL7A1-modified autologous fibroblasts and were followed up for 12 months. The primary outcome was safety, including autoimmune reactions against recombinant C7. Secondary outcomes included C7 expression, AF morphology, and presence of transgene in the injected skin.RESULTS Gene-modified fibroblasts were well tolerated, without serious adverse reactions or autoimmune reactions against recombinant C7. Regarding efficacy, there was a significant (P < 0.05) 1.26-fold to 26.10-fold increase in C7 mean fluorescence intensity in the injected skin compared with noninjected skin in 3 of 4 subjects, with a sustained increase up to 12 months in 2 of 4 subjects. The presence of transgene (codon-optimized COL7A1 cDNA) was demonstrated in the injected skin at month 12 in 1 subject, but no new mature AFs were detected.CONCLUSION To our knowledge, this is the first human study demonstrating safety and potential efficacy of lentiviral fibroblast gene therapy with the presence of COL7A1 transgene and subsequent C7 restoration in vivo in treated skin at 1 year after gene therapy. These data provide a rationale for phase II studies for further clinical evaluation.TRIAL REGISTRATION ClincalTrials.gov NCT02493816.FUNDING Cure EB, Dystrophic Epidermolysis Bullosa Research Association (UK), UK NIHR Biomedical Research Centre at Guy’s and St Thomas’ NHS Foundation Trust and King’s College London, and Fondation René Touraine Short-Exchange Award.

Authors

Su M. Lwin, Farhatullah Syed, Wei-Li Di, Tendai Kadiyirire, Lu Liu, Alyson Guy, Anastasia Petrova, Alya Abdul-Wahab, Fiona Reid, Rachel Phillips, Maria Elstad, Christos Georgiadis, Sophia Aristodemou, Patricia A. Lovell, James R. McMillan, John Mee, Snaigune Miskinyte, Matthias Titeux, Linda Ozoemena, Rashida Pramanik, Sonia Serrano, Racheal Rowles, Clarisse Maurin, Elizabeth Orrin, Magdalena Martinez-Queipo, Ellie Rashidghamat, Christos Tziotzios, Alexandros Onoufriadis, Mei Chen, Lucas Chan, Farzin Farzaneh, Marcela Del Rio, Jakub Tolar, Johann W. Bauer, Fernando Larcher, Michael N. Antoniou, Alain Hovnanian, Adrian J. Thrasher, Jemima E. Mellerio, Waseem Qasim, John A. McGrath

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Figure 4

Type VII collagen (C7) expression in subjects 2–5 at baseline and in injected and noninjected skin at 2 weeks, 3 months, and 12 months.

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Type VII collagen (C7) expression in subjects 2–5 at baseline and in inj...
(A) IF staining with a monoclonal LH7.2 antibody to C7 (targeting NC1 domain) on skin sections taken at specified time points from both injected (I) and noninjected (NI) sites alongside respective baseline samples. Trace C7 staining is visible in subjects 2 and 5, while brighter staining is seen in subjects 3 and 4. White arrows indicate the trace staining of C7 IF; asterisks indicate dermal-epidermal separation (B) The MFI of C7 NC1 expression along the DEJ in the injected and noninjected skin demonstrated in A for subjects 2–5 was further quantified for each sample in an assessor-blinded fashion using ImageJ, as adapted from a previous study (27). An average MFI value was calculated from 10 measurements taken at regular intervals using 8 × 8 pixels every 100 pixels along the DEJ. The C7 NCI MFI graphs in B correspond to the C7 IF images in A. (C) IF staining to demonstrate full-length C7 expression in subject 5 using a polyclonal antibody targeting the NC2 domain of C7 protein (ab198899; Abcam) after optimization. (D) The C7 NC2 MFI was then calculated using ImageJ as for the C7 NC1 MFI as described in B in an assessor-blinded fashion. The box-and-whisker plots in B and C represent the 10 repeat measurements of C7 MFI taken along the DEJ. *P < 0.05, **P < 0.005, ***P < 0.001. Error bars represent mean ± SEM. White arrows indicate C7 expression at the DEJ. B, baseline; C, control (normal skin); I, injected skin; M, month; NI, non-injected skin; W, week. Scale bars: 100 μm.