Pfizer week: AML donor-leukocyte trial posts results; three early trials advance

Four Pfizer-linked studies moved this week, from posted trial results to new recruiting starts.

• Brown University, with Pfizer as a collaborator, posted results for a completed Phase 1/2 study combining gemtuzumab ozogamicin with non-engraftment donor leukocyte infusions in relapsed or refractory acute myeloid leukemia. The study, sponsored by Brown University, enrolled patients in stages to assess safety, starting with 6 patients before expanding, with a cap of 18 patients total¹; actual enrollment reached 11.
• Pfizer began recruiting for a Phase 1 study of PF-08653945, a subcutaneous injection, in adults with overweight or obesity. The trial is designed to learn how the study medicine affects the body and how safe it is, using blood tests to measure drug levels², with an estimated enrollment of 57 participants.
• Pfizer opened a Phase 1 crossover study comparing relative bioavailability of prifetrastat tablets with differing particle size distributions in healthy adults. The study gives participants a single oral dose of prifetrastat, followed by a second oral dose at least 14 days later, in a randomized tablet sequence³, with an estimated enrollment of 32 participants.
• The University of Texas Health Science Center at Houston, with Pfizer as a collaborator, registered a not-yet-recruiting Phase 2 pilot study of zavegepant intranasal spray for episodic cluster headache. The primary outcome is the percentage of participants who achieve minimal pain, defined as 0 or 1 on a 0-4 scale, at 30 minutes after their first zavegepant dose⁴, with an estimated enrollment of 40 participants.