Fibrocell Teams with Castle Creek on RDEB Gene Therapy

Cell and gene therapy developer Fibrocell Science and rare dermatology disease focused Castle Creek Pharmaceuticals have teamed up to develop and commercialize Fibrocell’s lead gene therapy candidate, FCX-007, for the treatment of recessive dystrophic epidermolysis bullosa, a rare, life-threatening skin disease.

Recessive dystrophic epidermolysis bullosa (RDEB) is a genetic and progressive condition caused by the deficiency of collagen type VII (COL7). Severe cases of this condition involve widespread blistering that can lead to vision loss, disfigurement, and other serious medical problems. There is no cure or treatment approved in the United States.

FCX-007 is a genetically-modified autologous fibroblast that encodes the gene for COL7. By genetically modifying autologous fibroblasts ex vivo to produce COL7, culturing the cells, 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.

Fibrocell is planning a late-stage clinical trial designed as an open label, multi-centered, intra-patient-controlled study expected to enroll 15-20 patients. The trial is expected to begin enrollment in the second quarter of 2019.

“This agreement provides resources and non-dilutive capital to continue the development and, if approved, commercialize FCX-007, a potentially transformative treatment for RDEB patients,” said John Maslowski, president and CEO of Fibrocell.

Under the terms of the agreement, Fibrocell will receive up to $135 million, including an upfront payment of $7.5 million, $2.5 million for the first patient enrolled in the phase 3 clinical trial and $30 million upon approval and commercial readiness of the therapy. Fibrocell is also eligible to receive up to $75 million in sales milestones based on cumulative net sales. Castle Creek Pharmaceuticals will also pay Fibrocell a 30 percent share of the gross profits from FCX-007 sales.

Castle Creek will receive an exclusive license to commercialize FCX-007 in the United States. Castle Creek will be responsible for all development and manufacturing expenses up to $20 million prior to the initial filing for approval with the U.S. Food and Drug Administration. If development spending exceeds $20 million, Castle Creek will be responsible for 70 percent of the excess costs and Fibrocell will cover 30 percent of these additional expenses. Castle Creek will also be responsible for all commercialization activities for FCX-007. Fibrocell will maintain responsibility for clinical development, regulatory interactions, and manufacturing of the product under a future supply agreement with Castle Creek.  

Fibrocell will also retain sole ownership of the Rare Pediatric Disease Priority Review voucher, which may be granted upon market approval of FCX-007. The voucher, which is transferrable, can be used to accelerate the review for a subsequent application to market a therapy. GW Pharmaceuticals most recently sold a priority review voucher in March for $105 million.

FCX-007 is being developed in collaboration with Intrexon under which Fibrocell will pay Intrexon 50 percent of all upfront, milestone, and profit share payments from Castle Creek.

“We believe our collaboration with Fibrocell is synergistic and serves both of our long-term objectives well,” said Greg Wujek, CEO of Castle Creek Pharmaceuticals. “It increases the breadth of Castle Creek’s potential epidermolysis bullosa therapies by combining our clinical trial evaluating our investigational topical therapy for epidermolysis bullosa simplex with Fibrocell’s gene therapy to potentially treat RDEB.”

Photo: John Maslowski, president and CEO of Fibrocell

Author: Rare Daily Staff