Pelthos Therapeutics has agreed to merge with Castle Creek Biosciences under a definitive agreement, the companies reported on November 2, 2026. The purchase price was not disclosed in the sources. Castle Creek will merge with Pelthos, and the combined business will continue operating as Pelthos Therapeutics and trade on the NYSE American under the ticker PTHS.
According to the source, the combination creates a biotechnology company focused on serious diseases affecting the skin, bringing together commercial-stage dermatology products with late-stage cell and gene therapy technology. The transaction adds Castle Creek's fibroblast-based cell and gene therapy platform to Pelthos' existing dermatology portfolio and Nitricil technology. Pelthos currently has three FDA-approved products: ZELSUVMI, XEPI and XEGLYZE.
Castle Creek's lead program is D-Fi, or dabocemagene autoficel, an injectable and redosable gene-modified cell therapy being developed for dystrophic epidermolysis bullosa, a rare inherited skin disease caused by mutations in the COL7A1 gene that can result in chronic wounds and increased risk of squamous cell carcinoma. D-Fi has received Orphan Drug Designation and is expected to continue into Phase 3 development. It is administered through intradermal injection every other month and delivers cells designed to produce type VII collagen.
Under the transaction terms, Castle Creek stockholders will receive 5.2 million shares of Pelthos common stock at closing, representing approximately 32.5% of Pelthos' fully diluted shares, and may receive up to another 5.8 million shares following FDA approval of D-Fi. The agreement provides for up to $300 million in milestone payments, including $50 million upon achievement of specified Phase 3 clinical endpoints and up to $250 million tied to D-Fi's first commercial sale and specified net sales milestones. Castle Creek stockholders are also eligible to receive 80% of the net proceeds from any priority review voucher awarded following FDA approval of D-Fi.
The transaction is expected to close by the end of the first quarter of 2027. Scott Plesha will continue as CEO, while Peter Greenleaf will serve as Executive Chair.