Assembly Biosciences, Inc. announced the selection of development candidate ABI-6250 to progress to IND-enabling studies. ABI-6250, anally bioavailable small molecule entry inhibitor, is the first development candidate nominated by the company for the treatment of chronic hepatitis D virus (HDV) infection, and the second development candidate selected in 2023, following ABI-5366 for high-recurrence genital herpes. HDV is a virus that infects liver cells in people who are also infected with hepatitis B virus (HBV).

Patients with chronic HDV infection experience much higher rates of cirrhosis and liver cancer than those with chronic HBV infection only. In preclinical studies, ABI-6250 inhibited the interaction of HDV with sodium taurocholate co-transporting polypeptide (NTCP), the host receptor used by HBV/HDV to enter liver cells. Inhibiting viral entry by blocking NTCP is a clinically validated target for reducing HDV viremia and liver injury in patients.

In preclinical studies, ABI-6250 demonstrated low nanomolar potency against all tested HBV/HDV genotypes, favorable selectivity for NTCP versus other bile acid transporters, good oral bioavailability and a pharmacokinetic profile projected to support once-daily oral dosing. Assembly Bio plans to present data for ABI-6250 at future scientific conferences.