Gene therapy trial for blistering skin condition advancing to next stage

The companies behind the development of FCX-007, a gene therapy treatment for recessive dystrophic epidermolysis bullosa (RDEB), announced that safety data on the first of six patients treated with FCX-007 shows no adverse events.

RDEB is the most severe form of dystrophic epidermolysis bullosa (DEB), a congenital and progressive orphan skin disease caused by a deficiency of the protein type VII collagen (COL7).

It is a rare condition and in recent years, researchers have delved into the possibility of a major medical breakthrough for RDEB in a gene therapy called FCX-007 (Fibrocell Science Inc. and Intrexon Corp.) in which genetically modified cells are transplanted back into patients via intradermal injections.

“By genetically modifying autologous fibroblasts ex vivo to produce COL7, culturing them and then treating wounds locally via injection, FCX-007 offers the potential to address the underlying cause of the disease by providing high levels of COL7 directly to the affected areas while avoiding systemic distribution,” the companies announced in news release.

In May 2017, Fibrocell announced that safety data on the first of six RDEB patients treated with FCX-007 in the phase 1 portion of the phase 1/2 trial passed review by the Data Safety Monitoring Board, clearing the way for dosing additional adult patients. In June 2017, Fibrocell announced the dosing of two additional patients since the Data Safety Monitoring Board allowance.

Designing gene therapy

Recessive dystrophic epidermolysis bullosa, or RDEB, is caused by a mutation of the COL7A1 gene, which encodes for type VII collagen (COL7). The result is a COL7 deficiency.

Dr. Lane“One of the ways to approach this treatment is by doing genetic correction,” says Alfred Lane, M.D., a dermatologist, pediatrician and chief medical advisor for Fibrocell. “The genetic correction that Fibrocell and Intrexon are focused on involves taking the patient’s cells of the inner part of the skin, the fibroblasts; genetically correcting them, so they make the full length COL7; and then to use those cells to genetically correct them and then inject them back into the patient.”

With direct injection into the wounds, FCX-007 potentially targets the underlying cause of RDEB.

Researchers are testing the process in the phase 1/2 trial on existing wounds. The hope, according to Dr. Lane, is that FCX-007 will help to genetically correct especially trauma-prone areas of the skin, such as the elbows, the backs of knees and between the fingers.

“These patients develop mitt deformities, where they develop a blister between the fingers and that forms a scar. Then, the scar contracts and a new blister forms, and their fingers sort of pull into their hands. They have stubs instead of hands and fingers. By putting genetically corrected fibroblasts in those areas, we may really develop a process to prevent a lot of that damage,” he said. 

FCX-007 has been in development for more than four years, Dr. Lane said.

“In RDEB, the molecule is a mammoth. It’s one of the largest proteins in our body. And to do gene therapy, you have to have some way to carry that large piece of DNA into a patient’s cell. Intrexon developed the vector, and Fibrocell had developed the technology for culturing the fibroblasts and injecting them back into patients. Just this year have they been able to start dosing in the clinical trials,” he said.

Pediatric patients

RDEB patients have few treatment options, especially pediatric patients.

“There are many different wound dressings that are used in these children, but the major advance in the last 50 years has been to break blisters before they get bigger. We teach parents right from the very first day of life to break small blisters when they occur. The next major advancement occurred about 20 or 30 years ago when we started using feeding tubes for children who had difficulty swallowing or eating,” Dr. Lane said.

Recognizing the need for a treatment, the FDA granted FCX-007 Orphan Drug, Rare Pediatric Disease and Fast Track designations.

Fibrocell and Intrexon provided an update on the status of its pre-clinical trials for FCX-007 and also, FCX-013 for linear scleroderma. The presentations took place at the American Society of Gene and Cell Therapy (ASGCT) annual meeting in May 10-13, Washington, D.C.

Fibrocell expects to report 12-week post-treatment data for safety, mechanism of action and efficacy for multiple patients in the Phase 1 portion of the trial in the third quarter of 2017, according to a company press release.

To learn more about the FCX-007 Phase 1/2 clinical trial, please visit www.clinicaltrials.gov and search the identifier NCT02810951.

Disclosures:

This study is sponsored by Fibrocell Technologies Inc. in collaboration with Intrexon Corp. Dr. Lane is chief medical advisor for Fibrocell

References: 

“Fibrocell and Intrexon Announce Two Oral Presentations at the 20th Annual Meeting of the American Society of Gene & Cell Therapy,” Fibrocell Science Inc. and Intrexon Corp. news release, May 9, 2017. http://investors.dna.com/Fibrocell-and-Intrexon-Announce-Two-Oral-Presentations-at-the-20th-Annual-Meeting-of-the-American-Society-of-Gene-Cell-Therapy

“A Study of FCX-007 for Recessive Dystrophic Epidermolysis Bullosa (RDEB),” ClinicalTrials.gov identifier NCT02810951. https://www.clinicaltrials.gov/ct2/show/NCT02810951?term=fibrocell&rank=2