Pfizer posts hemophilia results, opens eczema Phase 3, ends two skin studies early

Pfizer had a busy week across hemophilia, dermatology, vaccines, and lupus programs, with one completed trial reporting results and two studies ending early.

• Hemophilia: The completed Phase 3 trial of PF-06741086 (marstacimab) in severe hemophilia A and moderately severe to severe hemophilia B posted results this week. Participants moved to marstacimab prophylaxis after a six-month observation phase during which they stayed on their existing hemophilia regimen.¹ The study enrolled 188 participants¹ and finished on 2025-04-29.
• Atopic dermatitis: Pfizer began recruiting for a new Phase 3 trial of tilrekimig (PF-07275315) in moderate-to-severe atopic dermatitis. The study will randomize participants to receive either tilrekimig or placebo at a 2:1 ratio², with an estimated enrollment of 375 and primary completion targeted for 2028-03-10.
• Seborrheic dermatitis/rosacea: A Phase 2 trial of topical PDE4 inhibitor PF-07038124, sponsored by Icahn School of Medicine at Mount Sinai with Pfizer as collaborator, was terminated early. The sponsor said the study ended early after interim analysis³, with 32 participants enrolled versus a planned 33-39 per condition.
• Lupus: Pfizer's Phase 2 trial of PF-06823859 in cutaneous and systemic lupus erythematosus with skin involvement was also terminated. The company said the decision was an internal business decision to not continue this study, not due to safety concerns or clinical effect reasons or requests from any regulatory authorities.⁴ Only 8 participants were enrolled against a planned 48.
• Vaccines: Pfizer opened recruitment for a Phase 3 trial of its 20-valent pneumococcal conjugate vaccine in healthy Chinese infants, comparing it to the approved 13-valent vaccine. The trial plans to enroll 1250 participants⁵ aged 42 to 98 days at consent, with primary completion estimated for 2028-11-30.
• Migraine registry: Pfizer is a collaborator, alongside the Association of Migraine Disorders and Lumiio Inc., on the observational HEADS Registry, which is recruiting toward an estimated 10,000 participants to track sinus, vestibular, auditory, and headache symptoms⁶ in U.S. adults.