Pfizer Discontinues Phase III Trial for Sickle Cell Treatment Amid Challenges in Patient Recruitment

- Pfizer terminated one of its two Phase III studies for the treatment of sickle cell disease due to slow patient recruitment.
- The study evaluated the anti-P-selectin antibody inclacumab, which was acquired by Pfizer from Global Blood Therapeutics (GBT) in a $5.4 billion deal.
- The trial faced "poor accrual" and associated recruitment challenges; it had enrolled only 78 out of the targeted 280 patients when terminated.
- Despite this setback, Pfizer still plans to seek FDA approval for inclacumab by 2026.
- Inclacumab has received both Orphan Drug and Rare Pediatric Disease designations from the FDA.
- The other Phase III study within the THRIVE program remains active with completed patient recruitment at 240 participants.
- The termination occurred after landmark gene therapy approvals for sickle cell disease by CRISPR Therapeutics and Vertex Pharmaceuticals (Casgevy), and bluebird bio (Lyfgenia).