Fibrocell, Castle Creek ink rare disease gene therapy pacts worth up to $135M

Fibrocell is enlisting Castle Creek Pharma’s help to push its midphase gene therapy for a rare genetic disorder through the clinic and onto the market. Castle Creek is licensing the program and will assume manufacturing and development costs up until the duo files for FDA approval. 

Fibrocell receives $7.5 million upfront, with another $2.5 million to follow when Castle Creek starts a phase 3 study for the candidate, FCX-007, in recessive dystrophic epidermolysis bullosa (RDEB). All told, Exton, Pennsylvania-based Fibrocell stands to pick up $135 million in other development and sales milestones, as well as a share of the gross profits. 

FXC-007 is currently in a phase 1/2 study in RDEB, a genetic disorder that causes the skin to blister easily. It is usually diagnosed in infancy. There are two types of RDEB; the milder form, known as the non-Hallopeau-Siemens type, is less severe, with blistering usually appearing in a few areas, such as the hands, feet and limbs. Babies born with the more severe form will have widespread blistering and areas where there is no skin. They may have even have blisters and scarring in their mouth and esophagus, making it difficult to eat and causing other problems down the road. 

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FCX-007 is an autologous treatment, meaning it is made from the patient’s own cells. Fibrocell takes fibroblasts—cells that make collagen—and genetically modifies them express the gene for a type of collagen missing in patients with RDEB. The modified cells are then injected into the patient’s wounds using a lentiviral vector, where they are expected to produce collagen and repair the damage. The phase 3 study is slated to start in the second quarter of this year and will enroll 15 to 20 patients, Fibrocell said in a statement. 

Castle Creek is working on its own treatment for a type of epidermolysis bullosa caused by a different mutation. 

“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 Fibrocell CEO John Maslowski, in the statement.  

And that’s not all—the deal will free up Fibrocell’s resources to advance its other programs: “With Castle Creek Pharmaceuticals providing funding for the development of FCX-007, Fibrocell can allocate additional resources to advance clinical development of FCX-013 for the treatment of moderate to severe localized scleroderma,” Maslowski said. Localized scleroderma is an autoimmune disease in which the skin becomes inflamed and hardens as a result of excess collagen. 

Like FX-007, the scleroderma treatment FX-013 is made from a patient’s own fibroblasts. But instead of being modified to produce collagen, cells used for FX-013 are modified to code for matrix metalloproteinase 1 (MMP-1), a protein that breaks down collagen. Fibrocell is enrolling patients for a phase 1 study of FX-013.