An Open-Label Study Investigating the 5-HT 2A Receptor Occupancy of Remlifanserin (ACP-204) With the PET Radioligand [ 18 F]Altanserin in Healthy Male Participants.
Clin Pharmacol Drug DevSep 1, 2026
Ethan S Burstein, Christine Sandiego, Brian Raether et al.
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In 30 seconds
This Phase 1 open-label study evaluated the 5-HT 2A receptor occupancy of remlifanserin (ACP-204) in 16 healthy male participants using PET imaging with [18F]altanserin. Results indicated that remlifanserin achieved receptor occupancy ranging from 53% to 100%, with an estimated EC50 of 0.37 ng/mL, demonstrating comparable potency to pimavanserin. Single doses were found to be safe and well tolerated.
Key findings
- Remlifanserin achieved 5-HT 2A receptor occupancy of 53%-100% at various plasma concentrations.
- The estimated EC50 for remlifanserin was 0.37 ng/mL, indicating its potency.
- Pimavanserin showed a receptor occupancy range of 41%-100% for comparison.
- Single doses of remlifanserin were safe and well tolerated in participants.
Why it matters
Understanding the receptor occupancy and safety profile of remlifanserin is crucial for its potential use in treating psychiatric disorders, as it may offer a new therapeutic option with a favorable safety profile.