Press Release

Assembly Biosciences to Present Data from HBV Core Inhibitor Programs at The International Liver Congress™ EASL 2021

June 9, 2021 at 8:00 AM EDT

SOUTH SAN FRANCISCO, Calif., June 09, 2021 (GLOBE NEWSWIRE) -- Assembly Biosciences, Inc. (Nasdaq: ASMB), a clinical-stage biotechnology company developing innovative therapeutics targeting hepatitis B virus (HBV), today announced that three abstracts have been accepted for presentation during the International Liver Congress™ 2021, the Annual Meeting of the European Association for the Study of the Liver (EASL) taking place virtually June 23-26, 2021. During the meeting, data from Assembly Bio’s three core inhibitor programs, vebicorvir (VBR), ABI-H2158 (2158) and ABI-H3733 (3733), will be featured in an oral presentation and two poster presentations.

“We’re pleased to join our esteemed colleagues on the global stage that EASL affords to present data on our next-generation core inhibitors, 2158 and 3733, and to share further learnings from previous studies of VBR, which we are advancing in two proof-of-concept multi-drug combination studies for the treatment of chronic hepatitis B infection,” said John McHutchison, AO, MD, Chief Executive Officer and President of Assembly Bio.

Presentation Details
Posters are expected to be made available to conference registrants through the online EASL portal at the start of the meeting on the morning of Wednesday, June 23, 2021. The posters and oral presentation will be available subsequently on the “Events & Presentations” page in the “Investors” section of Assembly Bio's website at www.assemblybio.com

Oral Presentation OS-2299: Second generation hepatitis B virus core inhibitors ABI-H2158 and ABI-H3733 have enhanced potency and target coverage for both antiviral inhibition and covalently closed circular DNA establishment activities
Session: Hepatitis B: Novel therapeutic approaches
Date: June 25 at 3:00 – 3:15 p.m. CET
Presenter: William Delaney, PhD, Chief Scientific Officer, Assembly Bio
Summary: VBR, 2158, and 3733 achieve plasma concentrations significantly above EC50 and protein-adjusted EC50 for antiviral activity. The next-generation compounds 2158 and 3733 show enhanced potency and exposures that cover cccDNA prevention at significant multiples above protein-adjusted EC50 at Cmin.

Poster PO-1286: No emergent core inhibitor resistance in patients with chronic hepatitis B virus infection treated with vebicorvir in combination with a nucleos(t)ide reverse transcriptase inhibitor 
Session: Viral hepatitis B/D: Therapy
Date: June 23 at 8:00 a.m. CET
Presenter: Man-Fung Yuen MD, PhD, Chief of Division of Gastroenterology and Hepatology, Queen Mary Hospital, Hong Kong
Summary: Sequence analyses were conducted for virologically-suppressed patients with chronic HBV enrolled in the Phase 2 Study 201 and open-label extension Study 211 of VBR in combination with a nucleos(t)ide reverse transcriptase inhibitor (NrtI) who discontinued treatment. Overall, most patients (78%) did not have detectable core inhibitor substitutions; for patients harboring a core inhibitor substitution (22%), no enrichment compared to baseline was observed after treatment was removed.

Poster PO-482: Viral response and safety following discontinuation of treatment with the core inhibitor vebicorvir and a nucleos(t)ide reverse transcriptase inhibitor in patients with HBeAg positive or negative chronic hepatitis B virus infection 
Session: Viral hepatitis B/D: Therapy
Date: June 23 at 8:00 a.m. CET
Presenter: Edward Gane, MBChB, MD FRACP, MNZM, New Zealand Liver Transplant Unit, Auckland City Hospital, New Zealand
Summary: In the Phase 2 Study 201 and open-label extension Study 211, VBR+NrtI resulted in deep on-treatment virologic suppression. Stopping criteria were applied and eligible patients discontinued both VBR+NrtI. Discontinuation of VBR+NrtI treatment was well-tolerated, but sustained virologic response was not achieved. Further data analyses suggest core-related antigen level may be important in future discontinuation criteria. Other studies with VBR+NrtI in multi-drug combinations will evaluate potential finite treatment regimens.

About HBV
Chronic hepatitis B virus (HBV) infection is a debilitating disease of the liver that afflicts approximately 270 million people worldwide with up to 90 million people in China, as estimated by the World Health Organization. HBV is a global epidemic that affects more people than hepatitis C virus (HCV) and HIV infection combined—with a higher morbidity and mortality rate. HBV is a leading cause of chronic liver disease and need for liver transplantation, and up to one million people worldwide die every year from HBV-related causes.

The current standard of care for patients with chronic HBV infection is life-long suppressive treatment with medications that reduce, but do not eliminate, the virus, resulting in very low cure rates. There is a significant unmet need for new therapies to treat HBV.

About Assembly Biosciences
Assembly Bio is a clinical-stage biotechnology company committed to bringing finite and curative therapies to the 270 million people living with hepatitis B virus (HBV) worldwide. A pioneer in the development of a new class of potent, oral core inhibitor drug candidates, Assembly Bio’s approach aims to break the complex viral replication cycle of HBV to free patients from a lifetime of therapy. Assembly Bio’s strategy toward cure includes a leading portfolio of more potent, next-generation core inhibitors, proof-of-concept combination studies and a research program focused on the discovery of novel HBV targets. For more information, visit assemblybio.com.

Forward-Looking Statements
The information in this press release contains forward-looking statements that are subject to certain risks and uncertainties that could cause actual results to materially differ. These risks and uncertainties include: Assembly Bio’s ability to initiate and complete clinical studies involving its therapeutic product candidates, including studies contemplated by Assembly Bio’s clinical collaboration agreements, in the currently anticipated timeframes; safety and efficacy data from clinical studies may not warrant further development of Assembly Bio’s product candidates; clinical and nonclinical data presented at conferences may not differentiate Assembly Bio’s product candidates from other companies’ candidates; continued development and commercialization of Assembly Bio’s product candidates, if successful, in the China territory will be dependent on, and subject to, Assembly Bio’s collaboration agreement governing its activity in the China territory; Assembly Bio’s ability to maintain financial resources necessary to continue its clinical studies and fund business operations; any impact that the COVID-19 pandemic may have on Assembly Bio’s business and operations, including initiation and continuation of its clinical studies or timing of discussions with regulatory authorities; and other risks identified from time to time in Assembly Bio’s reports filed with the U.S. Securities and Exchange Commission (the SEC). You are urged to consider statements that include the words may, will, would, could, should, might, believes, hopes, estimates, projects, potential, expects, plans, anticipates, intends, continues, forecast, designed, goal or the negative of those words or other comparable words to be uncertain and forward-looking. Assembly Bio intends such forward-looking statements to be covered by the safe harbor provisions contained in Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. More information about Assembly Bio’s risks and uncertainties are more fully detailed under the heading “Risk Factors” in Assembly Bio’s filings with the SEC, including its most recent Annual Report on Form 10-K, Quarterly Reports on Form 10-Q and Current Reports on Form 8-K. Except as required by law, Assembly Bio assumes no obligation to update publicly any forward-looking statements, whether as a result of new information, future events or otherwise.

Contacts

Investor and Corporate:
Lauren Glaser
Senior Vice President, Investor Relations and Corporate Affairs
(415) 521-3828
lglaser@assemblybio.com

Media:
Sam Brown Inc.
Audra Friis
(917) 519-9577
ASMBMedia@sambrown.com