Assembly Biosciences : Building Beyond Hepatitis B/D

Building Beyond Hepatitis B/D:

HSV-2 & Transplant-Associated Herpesviruses

Aug 31, 2022

Nasdaq: ASMB

©2020 ASSEMBLY BIOSCIENCES, INC.	1

Agenda

• Applying unparalleled expertise in virologic drug development to expand Assembly Bio's portfolio into new viral diseases
• • John McHutchison AO, MD, Chief Executive Officer at Assembly Bio
• Assembly Bio's differentiated antiviral approach for HSV-2 and an early look at the program for transplant-associated herpesvirus infections
• • William Delaney, PhD, Chief Scientific Officer at Assembly Bio
• Q&A with Sir Michael Houghton, PhD
• Update on 2022 Progress
• • John McHutchison

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Today's Speakers

John McHutchison AO, MD	William Delaney, PhD	Sir Michael Houghton, PhD
Chief Executive Officer	Chief Scientific Officer	Director, Li Ka Shing Applied Virology
		Institute, University of Alberta,
		Edmonton, Canada

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Cautionary Note Regarding Forward-Looking Statements

The information in this presentation 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 successfully execute its previously announced reprioritization and restructuring activities; potential adverse legal, reputational, operational and financial effects on Assembly Bio resulting from the reprioritization and restructuring activities; Assembly Bio's ability to initiate and complete clinical studies involving its therapeutic product candidates, including studies contemplated by Assembly Bio's 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; results of nonclinical studies may not be representative of disease behavior in a clinical setting and may not be predictive of the outcomes of clinical studies; continued development and commercialization of ABI-H3733, if successful, in the China territory will be dependent on, and subject to, Assembly Bio's collaboration agreement governing this 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, enrollment 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.

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Advancing a Clinical & Research Stage Portfolio of Small Molecules for HBV and Other Viral Diseases

HBV*		Next Gen CI†
	HBV/HDV
Herpes Viruses

		RESEARCH			DEVELOPMENT
Drug Candidate	Lead	Optimization	IND	Phase 1	Phase 2	Phase 3	China	Worldwide
Identification	Enabling	Rights	Rights
3733
4334
HBV/HDV
Entry Inhibitor
Interferon-α
Receptor Agonist

HSV-2Long-Acting

Helicase Inhibitor

Pan-herpes

Polymerase

Inhibitor (NNPI)

*While Assembly Bio has discontinued further development of first-generation core inhibitor, vebicorvir (VBR), a Phase 2 triple combination study conducted in collaboration with Arbutus Biopharma evaluating VBR + NrtI + Arbutus' investigational RNAi is ongoing.

† Next Generation Core Inhibitors ABI-H3733 (3733) and ABI-4334 (4334)

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