Pelthos Therapeutics Inc. filed a Form 425 communication on October 30, 2026, disclosing a definitive agreement to combine with Castle Creek Biosciences, a late-stage gene therapy developer, in a transaction expected to close by the end of the first quarter of 2027.

Key Highlights

  • Definitive agreement signed: Pelthos Therapeutics has entered into a definitive agreement to combine with Castle Creek Biosciences, according to the filing.
  • Castle Creek's lead asset: The combination centers on Castle Creek's D-Fi (dabocemagene autoficel; FCX-007) platform, described in the filing as a redosable gene therapy.
  • Expected closing timeline: The transaction is expected to be completed by the end of the first quarter of 2027, the filing states.
  • Combined board composition: Upon closing, the combined company's board will consist of 10 directors, including two designated by Castle Creek, per the filing.
  • Leadership continuity: Scott Plesha will continue as Chief Executive Officer of the combined company, and Peter Greenleaf will serve as Executive Chair, according to the filing.
  • Upcoming product launches: The filing references planned 2027 launches of XEPI for Impetigo and XEGLYZE for head lice, alongside the existing commercial product ZELSUVMI.
  • Exchange listing: Pelthos is listed on NYSE American, as noted in the filing's forward-looking statements section.

Pelthos and Castle Creek Biosciences Announce Combination Agreement

According to the Form 425 filing submitted by Pelthos Therapeutics Inc. (NYSE American:PTHS) on October 30, 2026, the company has entered into a definitive agreement to combine with Castle Creek Biosciences. The filing takes the form of an internal employee communication authored by Scott Plesha and distributed by email on that date. Castle Creek Biosciences is described in the filing as "a late-stage company developing redosable gene therapies."

The filing states that the combination is intended to unite Castle Creek's D-Fi platform, which the filing identifies by its full name dabocemagene autoficel (FCX-007), with Pelthos' "three novel FDA-approved products." The filing characterizes the combined portfolio as spanning "marketed, launch-stage and late-stage assets across multiple therapeutic modalities," and notes that Castle Creek's focus area builds on Pelthos' existing strength in dermatology, with particular emphasis on pediatric dermatology. The communication also references planned 2027 launches of XEPI for Impetigo and XEGLYZE for head lice as additions to the commercial portfolio alongside ZELSUVMI, which has already launched.

Until the transaction closes, the filing states that "Pelthos and Castle Creek will remain separate companies and continue to operate independently." On the governance structure after closing, the filing discloses that the combined company's board will consist of 10 directors, with two designated by Castle Creek. Scott Plesha will remain Chief Executive Officer and the current Pelthos management team will continue to lead the combined entity, while Peter Greenleaf will assume the role of Executive Chair. The filing includes extensive cautionary language identifying risks, including the possibility that the transaction may not be completed, regulatory approval challenges, and the risk that a concurrent private financing may not be consummated. All statements regarding expected benefits and timing are characterized by the filing as forward-looking and subject to those risks.

What Was Disclosed

Pelthos Therapeutics filed a Rule 425 employee communication on October 30, 2026, announcing a definitive merger agreement with Castle Creek Biosciences. The filing describes the expected closing timeline, post-closing leadership, board composition, and the combined company's planned product portfolio.