Assembly Biosciences Announces Program Reprioritization and Organizational Update

Assembly Biosciences, Inc.

– Discontinues clinical development of vebicorvir, Assembly Bio’s first-generation core inhibitor, based on interim efficacy data from ongoing combined clinical studies

– Advance significantly more potent, next-generation core inhibitors ABI-H3733 and ABI-4334 into clinical studies

– Prioritizes research activities including small molecule HBV/HDV entry inhibitor, small molecule interferon-α receptor agonist and two other undisclosed viral targets

– Reprioritized clinical programs and organizational restructuring extend cash trail to first half of 2024

SOUTH SAN FRANCISCO, Calif., July 20 10, 2022 (GLOBE NEWSWIRE) — Assembly Biosciences, Inc. (Nasdaq: ASMB), a clinical-stage biotechnology company developing innovative investigational therapies targeting hepatitis B virus (HBV) and other viral diseases, announced today halting development of its first-generation core inhibitor, vebicorvir (VBR), as it prioritizes the clinical development of its next-generation core inhibitors, ABI-H3733 (3733) and ABI-4334 (4334 ), and advancing its research pipeline. Assembly Bio will restructure the organization and reduce its workforce to align with these strategic objectives.

VBR program update

Assembly Biosciences will discontinue clinical development of its first-generation investigational core inhibitor, VBR, based on review of interim efficacy during treatment of the two ongoing VBR triple-combination studies. The data indicate that triple combinations do not show an advantage in several key viral parameters compared to double combinations without VBR in either study.

“By combining VBR with NrtI therapy, we achieved a faster and deeper level of viral suppression than with NrtI alone and we continued to see a favorable safety and tolerability profile for VBR. Unfortunately, we do not believe, based on the interim data from our current studies, that any of the three VBR combinations is likely to achieve a significant rate of functional cure for patients with chronic infection. by HBV,” said John McHutchison, AO, MD, Chief Executive Officer and President of Assembly Bio. “Our strategy remains data-driven, and while the data from our VBR program does not support conducting additional cure-focused clinical trials with this candidate, the work has greatly informed the clinical development programs of our core inhibitors. next generation and contributed to HBV. field. These next-generation candidates, 3733 and 4334, are significantly more potent and provide the secondary mechanism against ccDNA that we believe will be essential to end and cure HBV treatments.

As a result of these data, Study 203, an open-label Phase 2 study evaluating the triple combination of VBR + nucleos

Aubrey L. Morgan