Fibrocell Science, Inc. announced the completion of a collaboration agreement with Castle Creek Pharmaceuticals to develop and commercialize Fibrocell’s lead gene therapy candidate, FCX-007, for the treatment of recessive dystrophic epidermolysis bullosa (RDEB), a rare, life-threatening genetic disorder diagnosed at infancy with no cure or treatment approved by the U.S. Food and Drug Administration (FDA). Under the terms of the collaboration agreement, Castle Creek Pharmaceuticals will receive an exclusive license to commercialize FCX-007 in the United States. Castle Creek Pharmaceuticals will be responsible for all development and manufacturing expenses up to $20 million prior to the initial Biologics License Application (BLA) filing with the FDA. If development spending exceeds $20 million, Castle Creek Pharmaceuticals will be responsible for 70% of the excess costs and Fibrocell will cover 30% of these additional expenses. Castle Creek Pharmaceuticals 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 Pharmaceuticals.  Fibrocell will receive 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 BLA approval and commercial readiness. Fibrocell is also eligible to receive up to $75 million in sales milestones, consisting of $25 million when FCX-007 achieves $250 million in cumulative net sales and an additional $50 million upon attaining $750 million in cumulative net sales. In addition, Castle Creek Pharmaceuticals will pay Fibrocell a 30% share of the gross profits from FCX-007 sales.