Assembly Biosciences announced the U.S. Food and Drug Administration (FDA) has granted Fast Track designation to ABI-H2158 (2158) for the treatment of patients with chronic HBV infection. 2158 is Assembly’s second-generation core inhibitor, which is being evaluated in an ongoing global Phase 2 trial.

The Fast Track program is intended to facilitate the development and review of drug candidates that treat serious conditions and fill an unmet medical need. A drug candidate with Fast Track designation is eligible for greater access to the FDA for the purpose of expediting the drug product candidate's development, review and potential approval. The Company previously received Fast Track designation for its first-generation core inhibitor ABI-H0731, currently in Phase 2 development.

“We are pleased to have received Fast Track designation for our second-generation core inhibitor 2158 for the treatment of chronic hepatitis B virus infection, a condition that affects over 250 million people worldwide with more than one million infected individuals in the United States,” said Luisa Stamm, MD, PhD, Chief Medical Officer at Assembly Biosciences. “This designation holds several important advantages to expedite the development and regulatory review of 2158 and underscores the importance of providing novel treatments to patients.”

Assembly’s HBV portfolio includes three clinical-stage small molecules, all of which are HBV core inhibitors that target multiple steps of the HBV life cycle. In Phase 2 clinical trials, first-generation core inhibitor ABI-H0731 administered with nucleos(t)ide analogue reverse transcriptase inhibitor (NrtI) therapy has been well-tolerated, has shown statistically superior antiviral activity in HBV DNA suppression compared to NrtI therapy alone, and has demonstrated significant declines in pgRNA that may indicate decreased cccDNA levels. Assembly’s HBV portfolio also includes two potent second-generation candidates, ABI-H2158 in a Phase 2 clinical trial and ABI-H3733 in Phase 1 development.