15. Subsequent Events

Acquisition of Economic Interest in FCX-007

On February 24, 2025, Ligand Pharmaceuticals Incorporated (“Ligand”) entered into a Purchase and Sale Agreement with Castle Creek Biosciences, Inc., Castle Creek Biosciences, LLC (collectively, “Castle Creek”), and a syndicate of co-investors for which Ligand acted as representative (collectively, including Ligand, the “Purchasers”), to support Castle Creek’s autologous human fibroblast cell-based gene therapy genetically modified to express COL7, also known as FCX-007 (dabocemagene autoficel) Phase 3 clinical study, its lead candidate for patients with dystrophic

epidermolysis bullosa. Pursuant to the agreement, the Purchasers obtained for an aggregate purchase price of $75.0 million a high-single-digit royalty on worldwide sales of FCX-007 and warrants to purchase shares of Castle Creek Biosciences, Inc. Series D-1 Preferred Stock, which are exercisable until February 24, 2035. The Company paid $5.0 million for a mid-single-digit percentage portion of the high-single-digit royalty on worldwide sales of FCX-007 and 10,464 warrants to purchase shares of Castle Creek Biosciences, Inc. Series D-1 Preferred Stock.