Assembly Biosciences to Launch Phase 2 ABI-6250 Trials in PBC and PSC in Q1 2027
Assembly Biosciences plans to launch a Phase 2 basket study of oral NTCP inhibitor ABI-6250 in primary biliary cholangitis and primary sclerosing cholangitis in Q1 2027, following completion of Phase 1a and ongoing HDV development. A separate Phase 2 trial in hepatitis delta virus is set for Q4 2026.
1. ABI-6250 Clinical Expansion
Assembly Biosciences is expanding its ABI-6250 program into primary biliary cholangitis and primary sclerosing cholangitis, broadening the oral NTCP inhibitor’s application beyond chronic hepatitis delta virus infection. This move addresses significant unmet needs in PSC, which lacks any approved treatments, and in PBC patients with inadequate responses to existing therapies.
2. Planned Trial Timelines
The company plans to initiate a Phase 2 trial of ABI-6250 in hepatitis delta virus infection in Q4 2026, followed by a Phase 2 basket study in PBC and PSC set to begin in Q1 2027, pending regulatory feedback. A pre-IND meeting with the U.S. FDA has been held, providing constructive guidance for the cholestatic disease development path.
3. Mechanism and Supporting Data
ABI-6250 inhibits the sodium taurocholate co-transporting polypeptide to block bile acid uptake into hepatocytes and HDV entry. Phase 1a data demonstrated dose-dependent elevations in plasma bile acids, consistent with target engagement, and chronic toxicology studies support longer-term dosing in planned Phase 2 trials.