ASMB

– Expanded ABI-6250 clinical development into cholestatic liver diseases, including primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC) – – Completed $115 million gross financing to support advancement of pipeline programs through key development milestones – – GS-1179 (formerly ABI-1179) selected to advance in HSV HPI program, with Phase 2 initiation expected by year-end 2026 – – Cash runway projected into 2029, including first $75 million Gilead collaboration extension payment due in Q4 2026 – SOUTH SAN FRANCISCO, Calif., Aug. 13, 2026 (GLOBE NEWSWIRE) -- Assembly Biosciences, Inc. (Nasdaq: ASMB), a biotechnology company developing innovative therapeutics targeting serious viral and liver diseases, today reported financial results for the second quarter ended June 30, 2026, and recent business updates. “During the second quarter, we advanced several important strategic priorities, including expanding ABI-6250 into cholestatic liver diseases and strengthening our balance sheet through a successful financing to support the continued advancement of our pipeline," said Jason Okazaki, chief executive officer and president of Assembly Bio. "We were also pleased to receive Gilead’s clinical development plan for the HSV helicase primase inhibitor program, which includes plans for GS-1179 to advance into a Phase 2 clinical trial by the end of 2026. The plan also contemplates evaluation of GS-1179 across broader prevention settings, including in connection with HIV PrEP, further reinforcing the potential opportunity for this program. We expect to make our determination on whether to opt-in to the U.S. cost and profit share soon after we receive the commercial cost estimates from Gilead, which will complete the opt-in package.” Second Quarter 2026 and Recent Updates Announced expansion of ABI-6250 into cholestatic liver diseases, including PBC and PSC, with a Phase 2 study anticipated to initiate in the first quarter of 2027 Completed $115 million gross financing expected to extend funding beyond planned ABI-6250 Phase 2 studies in hepatitis delta virus (HDV) and cholestatic liver diseases Presented topline Phase 1a data for ABI-6250 at the European Association for the Study of the Liver (EASL) Congress 2026 and participated in several scientific and investor conferences during the quarter Received the clinical development plan from Gilead Sciences, Inc. (Gilead) for the herpes simplex virus (HSV) helicase-primase inhibitor (HPI) program. The plan indicates GS-1179 (formerly ABI-1179) has been selected to advance, with a Phase 2 clinical trial in participants with recurrent genital herpes expected to initiate by the end of 2026. The program is also being considered for possible evaluation as part of a combination strategy with HIV pre-exposure prophylaxis (PrEP). Assembly Bio’s decision to opt in to the 40% U.S. cost-profit share will be made after receipt and review of Gilead’s commercial cost estimates, which will complete the opt-in package. Anticipated Milestones and Events Following receipt of Gilead’s commercial cost estimates for the complete opt-in package for the HSV HPI program, determine by year-end 2026 whether to exercise Assembly Bio’s option to participate in a 40% U.S. cost-profit share in lieu of receiving U.S. milestones and royalties Initiate a Phase 2 clinical study evaluating ABI-6250 in participants with chronic HDV by year-end 2026 Initiate a Phase 2 clinical study evaluating ABI-6250 in participants with cholestatic liver diseases, including PBC and PSC, in the first quarter of 2027 Upcoming Conferences American Chemical Society (ACS) Fall 2026: August 23-27, 2026 – Chicago, Illinois International HBV Meeting: September 6-10, 2026 – Singapore ID Week: October 21-24, 2026 – Washington, D.C. American Association for the Study of Liver Diseases (AASLD): November 5-9, 2026 – Denver, Colorado GS-1179 and ABI-6250 are investigational product candidates that have not been approved anywhere globally, and their safety and efficacy have not been established. GS-1179 is exclusively licensed to Gilead under the collaboration between Assembly Bio and Gilead, and Gilead has the sole right and responsibility for further clinical development and commercialization of the HSV HPI program. Second Quarter 2026 Financial Results Cash, cash equivalents and marketable securities were $320.4 million as of June 30, 2026, compared to $226.6 million as of March 31, 2026. The company’s cash position, including the first $75 million extension fee due from Gilead in the fourth quarter of 2026 following the third anniversary of the collaboration agreement, is projected to fund operations into 2029. Revenue from collaborative research with Gilead was $13.4 million for the three months ended June 30, 2026, compared to $9.6 million for the same period in 2025. The increase reflects the timing of activities performed and progress toward completion of services under the Gilead Collaboration Agreement, and includes a $5.1 million cumulative catch-up adjustment related to updated estimates of future activities under the collaboration. Research and development expenses were $14.9 million for the three months ended June 30, 2026, compared to $16.1 million for the same period in 2025. The decrease was primarily driven by lower external program expenses due to the completion of clinical trials, partially offset by increased research and discovery activities and higher employee-related expenses. General and administrative expenses were $4.8 million for the three months ended June 30, 2026, compared to $4.6 million for the same period in 2025, primarily driven by increased stock-based compensation related to performance-based awards. Net loss attributable to common stockholders was $3.9 million, or $0.20 per basic and diluted share, for the three months ended June 30, 2026, compared to $10.2 million, or $1.33 per basic and diluted share, for the same period in 2025. The lower net loss was driven by increased revenue, lower research and development expenses and higher interest income from a larger cash balance following Assembly Bio’s recent financings. Lower net loss per share also reflects a higher weighted-average share count in 2026. About Assembly Biosciences Assembly Biosciences is a biotechnology company dedicated to the development of innovative small-molecule therapeutics aimed at advancing the treatment paradigm of serious viral and liver diseases and improving the lives of patients worldwide. Led by an accomplished leadership team in antiviral and liver disease drug development, Assembly Bio is committed to improving outcomes for people living with the chronic impacts of herpesvirus, hepatitis delta virus (HDV) infections, cholestatic liver diseases and hepatitis B virus (HBV). For more information, visit assemblybio.com. Forward-Looking StatementsThe 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 realize the potential benefits of its collaboration with Gilead, including all financial aspects of the collaboration and equity investments; Assembly Bio’s ability to initiate and complete clinical studies involving its therapeutic product candidates, including studies contemplated by Assembly Bio’s collaboration with Gilead, including studies conducted by Gilead, in the currently anticipated timeframes or at all; safety and efficacy data from clinical or nonclinical studies may not warrant further development of product candidates; clinical and nonclinical data may not differentiate product candidates from other companies’ candidates; Assembly Bio’s ability to maintain financial resources and secure additional funding necessary to continue its research activities, clinical studies, and other business operations; potential effects of changes in government regulation; 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; 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: Investors:Patrick TillMeru Advisors(484) [email protected] Media:Jamie StrachotaSam Brown LLC(703) [email protected]

– Completed Phase 1b studies for ABI-5366 and ABI-1179, helicase-primase inhibitors for recurrent genital herpes – – Completed chronic toxicology studies for ABI-6250, an oral small-molecule entry inhibitor candidate for chronic hepatitis delta virus; Phase 2 initiation anticipated Q4 2026 – SOUTH SAN FRANCISCO, Calif., May 07, 2026 (GLOBE NEWSWIRE) -- Assembly Biosciences, Inc. (Nasdaq: ASMB), a biotechnology company developing innovative therapeutics targeting serious viral diseases, today reported financial results for the first quarter ended March 31, 2026, and recent highlights. “The first quarter reflected steady progress across our portfolio as we continue advancing our discovery and development programs,” said Jason Okazaki, chief executive officer and president of Assembly Bio. “As we look ahead, we anticipate receiving Gilead’s development plan and budget for the herpesvirus program and will evaluate our cost and profit share opt-in decision by mid-2026 while continuing to advance ABI-6250 toward Phase 2 in hepatitis delta virus by year-end.” First Quarter 2026 and Recent Highlights Completed follow-up period for all participants in the Phase 1b portion of the studies for ABI-5366 and ABI-1179, reinforcing continued confidence in the safety and efficacy findings previously disclosed for both candidates Completed chronic toxicology studies for ABI-6250, establishing support for anticipated phase 2 doses Presented an oral presentation and three posters, including one late-breaker, highlighting interim Phase 1b data for ABI-5366 and ABI-1179 at the 2026 Congress of the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) in Munich, Germany Anticipated Milestones and Events By mid-2026, upon receipt of Gilead Sciences, Inc. (Gilead)’s development plan and budget for the helicase-primase inhibitor (HPI) program (ABI-5366 and ABI-1179) for recurrent genital herpes, Assembly Bio to determine whether to opt in to a 40% U.S. cost-profit share, in lieu of receiving U.S. milestones and royalties Initiation of a Phase 2 clinical study for ABI-6250 in participants with chronic hepatitis delta virus (HDV) infection expected in the fourth quarter of 2026 Upcoming Conferences European Association for the Study of the Liver (EASL) Congress: May 27-30, 2026 – Barcelona, Spain ABI-5366, ABI-1179 and ABI-6250 are investigational product candidates that have not been approved anywhere globally, and their safety and efficacy have not been established. ABI-5366 and ABI-1179 are exclusively licensed to Gilead under the collaboration between Assembly Bio and Gilead, and Gilead has the sole right and responsibility for further clinical development and commercialization of the HPI program. First Quarter 2026 Financial Results Cash, cash equivalents and marketable securities were $226.6 million as of March 31, 2026, compared to $248.1 million as of December 31, 2025. The company’s cash position is projected to fund operations into 2028. Revenue from collaborative research with Gilead was $8.2 million for the three months ended March 31, 2026, compared to $9.4 million for the same period in 2025. The decrease reflects the timing of activities performed and progress toward completion of services under the Gilead Collaboration Agreement. Research and development expenses were $14.9 million for the three months ended March 31, 2026, consistent with the same period in 2025, with increases in employee compensation and research and discovery activities offset by decreases in external program expenses due to the completion of clinical trials. General and administrative expenses were $4.7 million for the three months ended March 31, 2026, compared to $4.5 million for the same period in 2025, primarily driven by increased stock-based compensation related to performance-based awards. Net loss attributable to common stockholders was $9.1 million, or $0.54 per basic and diluted share, for the three months ended March 31, 2026, compared to $8.8 million, or $1.17 per basic and diluted share, for the same period in 2025, reflecting a higher weighted-average share count in 2026. About Assembly Biosciences Assembly Biosciences is a biotechnology company dedicated to the development of innovative small-molecule therapeutics designed to change the path of serious viral diseases and improve the lives of patients worldwide. Led by an accomplished team of leaders in virologic drug development, Assembly Bio is committed to improving outcomes for patients struggling with the serious, chronic impacts of herpesvirus, hepatitis B virus (HBV) and hepatitis delta virus (HDV) infections. 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 realize the potential benefits of its collaboration with Gilead, including all financial aspects of the collaboration and equity investments; Assembly Bio’s ability to initiate and complete clinical studies involving its therapeutic product candidates, including studies contemplated by Assembly Bio’s collaboration with Gilead, in the currently anticipated timeframes or at all; safety and efficacy data from clinical or nonclinical studies may not warrant further development of Assembly Bio’s product candidates; clinical and nonclinical data may not differentiate Assembly Bio’s product candidates from other companies’ candidates; Assembly Bio’s ability to maintain financial resources and secure additional funding necessary to continue its research activities, clinical studies, and other business operations; potential effects of changes in government regulation; 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; 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: Investors: Patrick Till Meru Advisors (484) 788-8560 [email protected] Media: Sam Brown LLC Jamie Strachota (703) 819-7647 [email protected]

Assembly Biosciences (ASMB) came out with quarterly earnings of $2.48 per share, beating the Zacks Consensus Estimate of a loss of $0.51 per share. This compares to a loss of $1.57 per share a year ago. These figures are adjusted for non-recurring items. This quarterly report represents an earnings surprise of +586.28%. A quarter ago, it was expected that this biotech drug developer would post a loss of $0.5 per share when it actually produced a loss of $0.72, delivering a surprise of -44%. Over the last four quarters, the company has surpassed consensus EPS estimates two times. Assembly Biosciences, which belongs to the Zacks Medical - Generic Drugs industry, posted revenues of $42.47 million for the quarter ended December 2025, surpassing the Zacks Consensus Estimate by 300.65%. This compares to year-ago revenues of $7.36 million. The company has topped consensus revenue estimates three times over the last four quarters. The sustainability of the stock's immediate price movement based on the recently-released numbers and future earnings expectations will mostly depend on management's commentary on the earnings call. Assembly Biosciences shares have lost about 19.1% since the beginning of the year versus the S&P 500's decline of 3.2%. While Assembly Biosciences has underperformed the market so far this year, the question that comes to investors' minds is: what's next for the stock? There are no easy answers to this key question, but one reliable measure that can help investors address this is the company's earnings outlook. Not only does this include current consensus earnings expectations for the coming quarter(s), but also how these expectations have changed lately. Empirical research shows a strong correlation between near-term stock movements and trends in earnings estimate revisions. Investors can track such revisions by themselves or rely on a tried-and-tested rating tool like the Zacks Rank, which has an impressive track record of harnessing the power of earnings estimate revisions. Ahead of this earnings release, the estimate revisions trend for Assembly Biosciences was mixed. While the magnitude and direction of estimate revisions could change following the company's just-released earnings report, the current status translates into a Zacks Rank #3 (Hold) for the stock. So, the shares are expected to perform in line with the market in the near future. You can see the complete list of today's Zacks #1 Rank (Strong Buy) stocks here. It will be interesting to see how estimates for the coming quarters and the current fiscal year change in the days ahead. The current consensus EPS estimate is -$0.50 on $10.6 million in revenues for the coming quarter and -$4.10 on $32.2 million in revenues for the current fiscal year. Investors should be mindful of the fact that the outlook for the industry can have a material impact on the performance of the stock as well. In terms of the Zacks Industry Rank, Medical - Generic Drugs is currently in the bottom 23% of the 250 plus Zacks industries. Our research shows that the top 50% of the Zacks-ranked industries outperform the bottom 50% by a factor of more than 2 to 1. Another stock from the broader Zacks Medical sector, TELA Bio, Inc. (TELA), has yet to report results for the quarter ended December 2025. The results are expected to be released on March 24. This company is expected to post quarterly loss of $0.18 per share in its upcoming report, which represents a year-over-year change of +21.7%. The consensus EPS estimate for the quarter has remained unchanged over the last 30 days. TELA Bio, Inc.'s revenues are expected to be $21 million, up 19% from the year-ago quarter. Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report Assembly Biosciences, Inc. (ASMB) : Free Stock Analysis Report TELA Bio, Inc. (TELA) : Free Stock Analysis Report This article originally published on Zacks Investment Research (zacks.com). Zacks Investment Research

– Successfully licensed helicase-primase inhibitor program for recurrent genital herpes to Gilead, including candidates ABI-5366 and ABI-1179, following positive Phase 1b interim data; development plan anticipated by mid-2026 – – Phase 2 initiation for ABI-6250, an oral small-molecule entry inhibitor candidate for chronic hepatitis delta virus, anticipated by end of 2026 – SOUTH SAN FRANCISCO, Calif., March 19, 2026 (GLOBE NEWSWIRE) -- Assembly Biosciences, Inc. (Nasdaq: ASMB), a biotechnology company developing innovative therapeutics targeting serious viral diseases, today reported financial results for the year ended December 31, 2025, and recent highlights. “2025 was a pivotal year for the Company, and we anticipate another strong year ahead,” said Jason Okazaki, chief executive officer and president of Assembly Bio. “Compelling Phase 1b data across ABI-5366 and ABI-1179 led to an early decision by Gilead to license the HPI program, validating the strength of our science and execution, as well as the potential for our long-acting, oral antivirals to meaningfully improve patient care. As we enter 2026, we are well positioned – both scientifically and financially – to build on this momentum as we continue advancing our broader pipeline.” Fourth Quarter 2025 and Recent Highlights Recurrent genital herpes Released positive interim Phase 1b data from two weekly dose cohorts of ABI-1179 and additional interim data from the ABI-5366 Phase 1b study, including unblinded safety data from two weekly cohorts released in August 2025 and a monthly oral proof-of-concept cohort Licensed helicase-primase inhibitor (HPI) program, including ABI-5366 and ABI-1179, to Gilead Sciences, Inc. (Gilead), receiving a net $35 million option fee under the ongoing collaboration agreement Completed dosing and follow-up for all participants in Phase 1a/b studies for ABI-5366 and ABI-1179 Viral hepatitis Gilead declined to exercise or defer its option on ABI-4334, a highly potent capsid assembly modulator candidate for chronic hepatitis B virus (HBV) infection Initiated a structured process to find a partner for ABI-4334 after regaining sole rights to the program Scientific conference presentations highlighted Presented interim Phase 1b data for ABI-5366 in a late-breaking oral presentation at the 38th Congress of the International Union Against Sexually Transmitted Infections (IUSTI)-Europe in Athens, Greece Presented Phase 1b data for ABI-4334 in a poster presentation at the American Association for the Study of Liver Diseases (AASLD), The Liver Meeting®, in Washington, D.C. Anticipated Milestones and Events By mid-2026, pending receipt of Gilead’s development plan and budget, determine whether to opt in to 40% U.S. cost-profit share for herpesvirus HPI program (ABI-5366 and ABI-1179), in lieu of receiving U.S. milestones and royalties Initiate a Phase 2 clinical study for ABI-6250 in participants with chronic hepatitis delta virus (HDV) by the end of 2026 Upcoming Conferences ABI-5366 and ABI-1179: Multiple abstracts accepted for presentation at the Congress of the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) taking place in Munich, Germany from April 17-21, 2026 ABI-6250: Phase 1a data for ABI-6250 accepted as a poster presentation at the European Association for the Study of the Liver (EASL) Congress taking place in Barcelona, Spain from May 27-30, 2026 ABI-5366, ABI-1179, ABI-6250 and ABI-4334 are investigational product candidates that have not been approved anywhere globally, and their safety and efficacy have not been established. Year-End 2025 Financial Results Cash, cash equivalents and marketable securities were $248.1 million as of December 31, 2025, compared to $232.6 million as of September 30, 2025, and $112.1 million as of the year ended December 31, 2024. The company’s cash position is projected to fund operations into 2028. Revenue from collaborative research with Gilead was $72.3 million for the year ended December 31, 2025, compared to $28.5 million in 2024. The increase reflects the increase in collaboration funding. Research and development expenses were $64.8 million for the year ended December 31, 2025, compared to $55.9 million in 2024. The increase is largely driven by an increase in spending on the HPI program, as both ABI-1179 and ABI-5366 saw significant enrollment in their respective Phase 1b clinical studies during the current year. General and administrative expenses were $19.6 million for the year ended December 31, 2025, compared to $18.0 million in 2024. The increase was primarily due to higher professional fees and increased stock-based compensation related to performance-based awards. Net loss attributable to common stockholders was $6.1 million, or $0.55 per basic and diluted share, for the year ended December 31, 2025, compared to $40.2 million, or $6.69 per basic and diluted share, in 2024. About Assembly Biosciences Assembly Biosciences is a biotechnology company dedicated to the development of innovative small-molecule therapeutics designed to change the path of serious viral diseases and improve the lives of patients worldwide. Led by an accomplished team of leaders in virologic drug development, Assembly Bio is committed to improving outcomes for patients struggling with the serious, chronic impacts of herpesvirus, hepatitis B virus (HBV) and hepatitis delta virus (HDV) infections. 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 realize the potential benefits of its collaboration with Gilead, including all financial aspects of the collaboration and equity investments; Assembly Bio’s ability to initiate and complete clinical studies involving its therapeutic product candidates, including studies contemplated by Assembly Bio’s collaboration with Gilead, in the currently anticipated timeframes or at all; safety and efficacy data from clinical or nonclinical studies may not warrant further development of Assembly Bio’s product candidates; clinical and nonclinical data may not differentiate Assembly Bio’s product candidates from other companies’ candidates; Assembly Bio’s ability to maintain financial resources and secure additional funding necessary to continue its research activities, clinical studies, and other business operations; potential effects of changes in government regulation; 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; 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: Investors: Patrick Till Meru Advisors (484) 788-8560 [email protected] Media: Sam Brown LLC Alyssa Kuciunas (331) 481-3751 [email protected]

Supernus Pharmaceuticals (SUPN) came out with quarterly earnings of $0.92 per share, beating the Zacks Consensus Estimate of $0.28 per share. This compares to earnings of $0.75 per share a year ago. These figures are adjusted for non-recurring items. This quarterly report represents an earnings surprise of +228.57%. A quarter ago, it was expected that this drugmaker would post earnings of $0.82 per share when it actually produced earnings of $1.01, delivering a surprise of +23.17%. Over the last four quarters, the company has surpassed consensus EPS estimates four times. Supernus, which belongs to the Zacks Medical - Generic Drugs industry, posted revenues of $211.57 million for the quarter ended December 2025, surpassing the Zacks Consensus Estimate by 7.57%. This compares to year-ago revenues of $174.16 million. The company has topped consensus revenue estimates four times over the last four quarters. The sustainability of the stock's immediate price movement based on the recently-released numbers and future earnings expectations will mostly depend on management's commentary on the earnings call. Supernus shares have added about 2% since the beginning of the year versus the S&P 500's decline of 0.1%. While Supernus has outperformed the market so far this year, the question that comes to investors' minds is: what's next for the stock? There are no easy answers to this key question, but one reliable measure that can help investors address this is the company's earnings outlook. Not only does this include current consensus earnings expectations for the coming quarter(s), but also how these expectations have changed lately. Empirical research shows a strong correlation between near-term stock movements and trends in earnings estimate revisions. Investors can track such revisions by themselves or rely on a tried-and-tested rating tool like the Zacks Rank, which has an impressive track record of harnessing the power of earnings estimate revisions. Ahead of this earnings release, the estimate revisions trend for Supernus was unfavorable. While the magnitude and direction of estimate revisions could change following the company's just-released earnings report, the current status translates into a Zacks Rank #5 (Strong Sell) for the stock. So, the shares are expected to underperform the market in the near future. You can see the complete list of today's Zacks #1 Rank (Strong Buy) stocks here. It will be interesting to see how estimates for the coming quarters and the current fiscal year change in the days ahead. The current consensus EPS estimate is $0.27 on $187.46 million in revenues for the coming quarter and $2.50 on $850.57 million in revenues for the current fiscal year. Investors should be mindful of the fact that the outlook for the industry can have a material impact on the performance of the stock as well. In terms of the Zacks Industry Rank, Medical - Generic Drugs is currently in the bottom 34% of the 250 plus Zacks industries. Our research shows that the top 50% of the Zacks-ranked industries outperform the bottom 50% by a factor of more than 2 to 1. One other stock from the same industry, Assembly Biosciences (ASMB), is yet to report results for the quarter ended December 2025. This biotech drug developer is expected to post quarterly loss of $0.51 per share in its upcoming report, which represents a year-over-year change of +67.5%. The consensus EPS estimate for the quarter has remained unchanged over the last 30 days. Assembly Biosciences' revenues are expected to be $10.6 million, up 44% from the year-ago quarter. Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report Supernus Pharmaceuticals, Inc. (SUPN) : Free Stock Analysis Report Assembly Biosciences, Inc. (ASMB) : Free Stock Analysis Report This article originally published on Zacks Investment Research (zacks.com). Zacks Investment Research

– 98% reduction in HSV-2 shedding rate, >99% reduction in high viral load shedding rate and 91% reduction in virologically confirmed genital lesion rate observed in 50 mg weekly oral dose of ABI-1179, exceeding expectations for the study – – 76% reduction in HSV-2 shedding rate, 81% reduction in high viral load shedding rate and 88% reduction in virologically confirmed genital lesion rate observed in proof-of-concept test of monthly oral dose of ABI-5366 – – Company to hold conference call today at 6 p.m. ET – SOUTH SAN FRANCISCO, Calif., Dec. 08, 2025 (GLOBE NEWSWIRE) -- Assembly Biosciences, Inc. (Nasdaq: ASMB), a biotechnology company developing innovative therapeutics targeting serious viral diseases, today announced positive interim results from two Phase 1b studies of its investigational long-acting herpes simplex virus (HSV) helicase-primase inhibitors in participants seropositive for HSV type 2 (HSV-2) with recurrent genital herpes. These interim results include the first reported Phase 1b data for ABI-1179, evaluating weekly oral dosing. For ABI-5366, the reported data is for a monthly oral dosing regimen, following the positive interim results for weekly oral dosing reported earlier this year. “As we saw with ABI-5366, weekly oral dosing of ABI-1179 outperformed our expectations for antiviral efficacy and improvement in clinical outcomes, and we are thrilled with these Phase 1b findings for both highly promising candidates,” said Anuj Gaggar, MD, PhD, chief medical officer of Assembly Bio. “The ABI-5366 monthly oral dosing results are also encouraging and show significant reductions in viral shedding and virologically confirmed genital lesion rate, supporting the continued optimization of exposure to evaluate its potential for monthly oral dosing. We expect to pursue such optimization efforts in parallel with moving once-weekly ABI-5366 regimens into longer-duration Phase 2 clinical studies, which we plan to initiate in mid-2026. In parallel, we are evaluating the potential to also advance ABI-1179 into Phase 2 clinical evaluation and are progressing Phase 2 enabling activities for this candidate.” In the ABI-1179 study, highly potent antiviral activity was observed with a 98% reduction in HSV-2 shedding rate compared to placebo (p<0.01) over the 29-day evaluation period in the 50 mg weekly dose cohort. This reduction exceeds Assembly Bio’s target for the study of an 80%-85% reduction in HSV-2 shedding rate. Further, data revealed a 91% reduction in virologically confirmed genital lesion rate compared to placebo (p<0.01) with the 50 mg weekly dose. There was also a >99% reduction in the number of samples with high viral load, a potential surrogate for HSV-2 transmission and a secondary endpoint. ABI-1179 was observed to be well-tolerated at oral doses up to 50 mg weekly and the observed pharmacokinetic (PK) profile continues to support once-weekly oral dosing regimens. In the ABI-5366 monthly dose cohort, potent antiviral activity was observed, with a 76% reduction in HSV-2 shedding rate compared to placebo (p<0.01) over the 29-day evaluation period. The majority of positive swabs (89%) were collected in the last two weeks of the evaluation period when drug levels were declining. An 88% reduction in virologically confirmed genital lesion rate (p=0.01), along with an 81% reduction in the number of samples with high viral load (p<0.01) compared to placebo, was observed. As previously reported for the 350 mg weekly dose cohort, a 94% reduction in HSV-2 shedding rate (p<0.01) and a 97% reduction in virologically confirmed genital lesion rate (p<0.05) compared to placebo was observed. ABI-5366 continues to be well-tolerated across all evaluated oral dosing regimens up to 350 mg weekly, and the PK profile supports both once-weekly and potentially once-monthly oral dosing regimens. Under the collaboration agreement between Assembly Bio and Gilead Sciences, Inc. (Gilead), Gilead has the right to opt in to an exclusive license for further development and commercialization of the helicase-primase inhibitor program, with the first option timepoint extending through the review of an option data package to be delivered by Assembly Bio following the end of the Phase 1b studies. ABI-1179 was contributed by Gilead under the collaboration between Assembly Bio and Gilead. ABI-5366 and ABI-1179 are investigational product candidates that have not been approved anywhere globally, and their safety and efficacy have not been established. Study ABI-1179-101 – Interim Phase 1b Results Interim Results The Phase 1b interim analysis includes data from cohort B1, evaluating a 50 mg weekly oral dose and cohort B2, evaluating a 20 mg weekly oral dose, through the data cutoff date of November 25, 2025. Fifty participants have been enrolled in the 50 mg and 20 mg cohorts; 40 assigned to ABI-1179 (20 participants in each cohort) and 10 assigned to placebo (five in each cohort). Forty-six participants from these cohorts have completed the 29-day evaluation period while three discontinued treatment; one discontinued due to being lost to follow-up and two for other reasons not related to adverse events or study treatment. One participant was enrolled in the 20 mg cohort but did not receive treatment. Antiviral activity and clinical outcomes by treatment arm are summarized below. For this analysis, Assembly Bio also looked at whether participant-reported lesions were confirmed with any positive HSV-2 swab taken during the duration of the reported lesion. Both virologically confirmed and overall lesion rates are provided for both ABI-1179 and ABI-5366 studies. PBO=placebo; QW=once weekly; SD=standard deviation. All outcomes measured over evaluation period. a HSV-2 shedding rate calculated as the number of positive HSV-2 anogenital swabs divided by the total number of swabs collected. b High viral load shedding rate calculated as the number of positive HSV-2 anogenital swabs with HSV-2 >104 copies/mL divided by the total number of swabs collected. c Overall genital lesion rate calculated as the number of days with genital lesions of any kind present (including non HSV-2-associated lesions) divided by the total number of days assessed. d Virologically confirmed lesion rate calculated as the number of days with genital lesions associated with positive HSV-2 anogenital swabs present divided by the total number of days assessed. Statistically significant reductions were observed in the viral shedding rate, high viral load shedding rate, and virologically confirmed genital lesion rate for both the 50 mg and 20 mg cohorts compared to placebo as summarized below. PBO=placebo; QW=once weekly; High viral load = >104 HSV DNA copies/mL a Statistical analysis conducted using Poisson regression models and the corresponding p-values estimated accordingly. b P-value cannot be reliably calculated given the >99% reduction compared to placebo. The observed difference is consistent with a highly significant effect. Across the 50 mg and 20 mg cohorts, ABI-1179 demonstrated a PK profile that continues to support once-weekly dosing. ABI-1179 was observed to be well-tolerated at oral doses up to 50 mg weekly in participants seropositive for HSV-2 with recurrent genital herpes. As the study is ongoing, individual treatment assignments remain blinded. Overall, the proportion of participants reporting treatment-emergent adverse events (TEAEs) was similar between ABI-1179 (80%) and placebo (88.9%) recipients. Of the TEAEs reported, the majority were grade 1 or grade 2. The most common adverse events were upper respiratory tract infections and headaches. There have been no serious adverse events reported to date. One grade 3 adverse event of migraine was reported in a participant enrolled in the 20 mg/placebo cohort. The proportion of participants reporting treatment-emergent laboratory abnormalities was higher in placebo (44.4%) than in ABI-1179 (32.5%) recipients, with all observed abnormalities grade 1 or grade 2. Study ABI-5366-101 – Interim Phase 1b Monthly Dosing Results Interim Results The Phase 1b interim monthly dosing cohort analysis includes data from cohort B3, evaluating five loading doses of 350 mg given over seven days (the monthly cohort) through the data cutoff date of November 25, 2025. After this loading dose period, the evaluation period extended for 29 days with no further dosing as a simulation of a monthly dosing regimen. Additionally, final unblinded data from cohort B1, evaluating a loading dose of 150 mg and weekly doses of 30 mg (the 150/30 mg cohort), and cohort B2, evaluating a loading dose and weekly doses of 350 mg (the 350 mg cohort), are included. Seventy-six participants have been enrolled in the 150/30 mg, 350 mg and the monthly cohorts; 61 assigned to ABI-5366 (20 participants in each of the 150/30 mg and 350 mg cohorts, 21 in the monthly cohort) and 15 assigned to placebo (five in each cohort). Sixty-nine participants from these cohorts have completed the 29-day evaluation period while seven discontinued treatment; one due to an adverse event (described below), one due to follow-up, two withdrew consent and three for other reasons not related to adverse events or study treatment. Antiviral activity and clinical outcomes by treatment arm are summarized below. PBO=placebo; QW=once weekly; SD=standard deviation; High viral load = >104 HSV DNA copies/mL. All outcomes measured over evaluation period. a HSV-2 shedding rate calculated as the number of positive HSV-2 anogenital swabs divided by the total number of swabs collected. b High viral load shedding rate calculated as the number of positive HSV-2 anogenital swabs with HSV-2 >104 copies/mL divided by the total number of swabs collected. c Overall genital lesion rate calculated as the number of days with genital lesions of any kind present (including non HSV-2 associated lesions) divided by the total number of days assessed. d Virologically confirmed lesion rate calculated as the number of days with genital lesions associated with positive HSV-2 anogenital swabs present divided by the total number of days assessed. Statistically significant reductions were observed in the viral shedding rate, high viral load shedding rate, overall genital lesion rate and virologically confirmed genital lesion rate for both the 350 mg QW and monthly cohorts compared to placebo as summarized below. PBO=placebo; QW=once weekly; High viral load = >104 HSV DNA copies/mL a Statistical analysis conducted using Poisson regression models and the corresponding p-values estimated accordingly. Across the 150/30 mg, 350 mg QW and monthly cohorts, ABI-5366 demonstrated a PK profile that continues to be supportive of once-weekly and potentially once-monthly dosing. ABI-5366 was observed to be well-tolerated at all dose levels tested in participants seropositive for HSV-2 with recurrent genital herpes. While cohorts B1 and B2 are complete and unblinded safety data are reported, cohort B3 is ongoing and data remains blinded for this cohort. Safety data are summarized below. PBO=placebo; QW=once weekly Overall, across all cohorts, the proportion of participants reporting TEAEs was similar between ABI-5366 (95.1%) and placebo (93.3%) recipients. Of the TEAEs reported, all were grade 1 or grade 2. One grade 3 adverse event of hypertriglyceridemia was reported in a participant with relevant medical history who had grade 4 elevated triglycerides pre-dose on Day 1. This adverse event resulted in study discontinuation but following closure of the cohort was reassessed and was not considered treatment emergent or treatment related. The proportion of participants reporting treatment emergent laboratory abnormalities was similar in placebo (66.7%) and ABI-5366 (68.9%) recipients, with the majority of observed abnormalities being grade 1 or grade 2. There were three participants with treatment-emergent grade 3 laboratory abnormalities, all in the unblinded cohorts B1 and B2, and all are considered unrelated to assigned treatment: an exercise-associated elevation in creatine kinase (150/30 mg QW), an elevation of cholesterol in the follow-up period in a participant that had a grade 2 elevation at baseline (350 mg QW) and a participant with decreased neutrophils (placebo). There did not appear to be a dose-response relationship in either the frequency or severity of TEAEs or laboratory abnormalities. There have been no serious adverse events reported to date. ABI-1179-101 Study Overview ABI-1179-101 is a randomized, blinded, placebo-controlled Phase 1a/b clinical study. Positive interim data have been previously reported for Part A (Phase 1a), evaluating the safety, tolerability and PK of ABI-1179 following single dose administration in healthy participants. Part B (Phase 1b), in participants seropositive for HSV-2 with recurrent genital herpes, is evaluating weekly oral dosing regimens over a 29-day period in up to four cohorts randomized 20:5 between ABI-1179 and placebo with a pooled placebo analysis. Dosing is ongoing for cohort B3, evaluating a 10 mg weekly dosing regimen of ABI-1179. Part B also evaluates antiviral activity by measuring changes in viral parameters including shedding rate, quantification of HSV-2 DNA levels obtained from anogenital swab samples, and clinical parameters including genital lesion rate and duration. Due to the observed half-life of ABI-1179, the safety follow-up period for participants extends for 29 days after dosing (Day 57), with safety data available as of the data cutoff date through Day 57 for all participants from these cohorts that completed the evaluation period. The study uses pooled data from placebo recipients across cohorts as a control. As additional placebo recipients are enrolled in later cohorts, the sample size for the pooled placebos will change, which is expected to result in adjustments to both the observed effect sizes compared to placebo and the tests of statistical significance for those observed effects. Additional information about the Phase 1a/b trial is available at clinicaltrials.gov using the identifier NCT06698575. ABI-5366-101 Study Overview ABI-5366-101 is a randomized, blinded, placebo-controlled Phase 1a/b clinical study. Positive interim data have been previously reported for Part A (Phase 1a), evaluating the safety, tolerability and PK of ABI-5366 following single dose administration in healthy participants. Positive interim data have also previously been reported for two weekly oral dosing regimens over a 29-day period in Part B (Phase 1b, cohorts B1 and B2), in participants seropositive for HSV-2 with recurrent genital herpes. Part B of the study enrolled three cohorts randomized 20:5 between ABI-5366 and placebo with a pooled placebo analysis. Safety follow up is ongoing for cohort B3. Part B also evaluates antiviral activity by measuring changes in viral parameters including shedding rate, quantification of HSV-2 DNA levels obtained from anogenital swab samples, and clinical parameters including genital lesion rate and duration. Due to the long half-life of ABI-5366, the safety follow-up period for participants extends for 98 days after dosing (Day 127), with all safety data available as of the data cutoff date for all participants in cohorts B1 and B2 and up to Day 43 for all participants from the B3 cohort that completed the evaluation period. Complete, unblinded safety data are included for cohorts B1 and B2, with blinded safety data for cohort B3. The study uses pooled data from placebo recipients across cohorts as a control. As additional data for placebo recipients from cohort B3 become available, it is expected to result in adjustments to both the observed effect sizes compared to placebo and the tests of statistical significance for those observed effects. Additional information about the Phase 1a/b trial is available at clinicaltrials.gov using the identifier NCT06385327. Webcast and Conference Call Information Assembly Bio will be hosting a live webcast today at 6 p.m. ET. The live webcast can be accessed on the Investors section on the Company’s website at https://investor.assemblybio.com/events-presentations. A replay of the webcast will be available following the call. About Recurrent Genital Herpes Genital herpes is a chronic viral infection caused by HSV that can result in painful genital lesions, serious psychological and social impacts, and an increased risk of acquiring human immunodeficiency virus (HIV). Epidemiologic studies estimate over four million people in the United States, France, Germany, Italy, Spain and the United Kingdom experience recurrent genital herpes, with most people with initial symptomatic genital HSV-2 infection having three or more recurrences per year. While genital herpes can be caused by either HSV type 1 (HSV-1) or HSV-2, recurrences are more likely to be experienced by individuals infected by HSV-2. The current standard of care for recurrent genital herpes is nucleoside analogs given intermittently for recurrences or as daily chronic suppressive therapy; however, these are only partially effective in preventing recurrences and in reducing transmission of the virus. No new drugs have been approved in the United States or Europe to treat genital herpes for more than 25 years. About Helicase-Primase Inhibition HSV helicase-primase inhibitors target the viral helicase-primase complex, an essential viral enzyme complex that is conserved across both HSV-1 and HSV-2 and has no host equivalent. Inhibition of the helicase-primase complex is a clinically validated mechanism that has shown the potential for superior efficacy to the current standard of care, nucleoside analogs, in short-duration clinical studies in participants with recurrent genital herpes. About Assembly Biosciences Assembly Biosciences is a biotechnology company dedicated to the development of innovative small-molecule therapeutics designed to change the path of serious viral diseases and improve the lives of patients worldwide. Led by an accomplished team of leaders in virologic drug development, Assembly Bio is committed to improving outcomes for patients struggling with the serious, chronic impacts of herpesvirus, hepatitis B virus (HBV) and hepatitis delta virus (HDV) infections. 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 realize the potential benefits of its collaboration with Gilead, including all financial aspects of the collaboration and equity investments; Assembly Bio’s ability to initiate and complete clinical studies involving its therapeutic product candidates, including studies contemplated by Assembly Bio’s collaboration with Gilead, in the currently anticipated timeframes or at all; safety and efficacy data from clinical or nonclinical studies may not warrant further development of Assembly Bio’s product candidates; clinical and nonclinical data may not differentiate Assembly Bio’s product candidates from other companies’ candidates; Assembly Bio’s ability to maintain financial resources and secure additional funding necessary to continue its research activities, clinical studies, and other business operations; potential effects of changes in government regulation, including as a result of the change in U.S. administration in 2025; 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; 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 Investors: Meru Advisors Patrick Till (415) 788-8560 [email protected] Media: Sam Brown LLC Alyssa Kuciunas (331) 481-3751 [email protected]

– Released positive Phase 1b interim results for long-acting helicase-primase inhibitor candidate ABI-5366 showing significant reductions in viral shedding rate and genital lesion rate in recurrent genital herpes – – Announced Phase 1a interim results for orally bioavailable HDV entry inhibitor candidate ABI-6250 supporting progression into Phase 2 evaluation – – Additional interim Phase 1b data readouts from HSV program anticipated to include monthly oral dosing for ABI-5366 and two cohorts of weekly oral dosing for ABI-1179, with data now expected by end of year – – Raised $175 million gross proceeds from equity financings – SOUTH SAN FRANCISCO, Calif., Nov. 10, 2025 (GLOBE NEWSWIRE) -- Assembly Biosciences, Inc. (Nasdaq: ASMB), a biotechnology company developing innovative therapeutics targeting serious viral diseases, today reported financial results and recent updates for the third quarter ended September 30, 2025. “Our third quarter was marked by significant progress across our pipeline and important data releases, particularly the impressive interim antiviral activity and clinical outcomes data from our Phase 1b study for ABI-5366 in participants with recurrent genital herpes,” said Jason Okazaki, chief executive officer and president of Assembly Bio. “The $175 million equity investment we completed in August enables us to advance both our HSV and HDV programs into Phase 2 while continuing our efforts to discover and develop new programs. With enrollment in our Phase 1b study for ABI-5366 and two cohorts in our Phase 1b study for ABI-1179 now complete, we look forward to sharing additional data updates from our HSV program later this year.” Third Quarter 2025 and Recent Highlights Herpes Simplex Virus (HSV) Released positive interim results from a Phase 1b study of ABI-5366, a long-acting helicase-primase inhibitor development candidate, demonstrating significant reductions in HSV type 2 (HSV-2) shedding rate, high viral load shedding and genital lesion rates in participants with recurrent genital herpes Completed enrollment in the ongoing Phase 1b study of ABI-5366 in participants with recurrent genital herpes Completed enrollment in two cohorts of the ongoing Phase 1b study in participants with recurrent genital herpes for ABI-1179, a second long-acting helicase-primase inhibitor development candidate Presented interim Phase 1b data for ABI-5366 in a late-breaking oral presentation at the 38th Congress of the International Union Against Sexually Transmitted Infections (IUSTI)-Europe Hepatitis D Virus (HDV) Released interim results from a Phase 1a study of ABI-6250, an oral HDV entry inhibitor candidate, showing a pharmacokinetic profile supporting once-daily dosing, and dose-dependent increases in a biomarker of target engagement supporting progression to Phase 2 clinical evaluation in HDV Completed enrollment and follow-up period in the Phase 1a study of ABI-6250 in healthy participants Presented preclinical profiling of ABI-6250 in an oral presentation at the 2025 International HBV meeting Hepatitis B Virus (HBV) Presented positive data from a Phase 1b study for ABI-4334, a next-generation, highly potent HBV capsid assembly modulator candidate, in a late-breaking poster presentation at the American Association for the Study of Liver Diseases (AASLD), The Liver Meeting® Financing Raised $175 million in gross proceeds from equity financing with key institutional investors, strengthening financial position to support ongoing and future clinical development Anticipated Milestones and Events Mr. Okazaki and Anuj Gaggar, MD, PhD, chief medical officer, will present in a fireside chat during the Guggenheim 2nd Annual Healthcare Innovation Conference on November 12, 2025 Interim Phase 1b data readout for the HSV program in participants with recurrent genital herpes now anticipated by end of year from two cohorts of weekly dosing of ABI-1179 and one cohort of monthly dosing of ABI-5366. These datasets are expected to be announced together once all virology analyses are completed Initiation of a Phase 2 clinical study of ABI-5366 anticipated in mid-2026 ABI-1179 was contributed by Gilead Sciences, Inc. (Gilead) under the collaboration between Assembly Bio and Gilead. ABI-5366, ABI-1179, ABI-6250 and ABI-4334 are investigational product candidates that have not been approved anywhere globally, and their safety and efficacy have not been established. Third Quarter 2025 Financial Results Cash, cash equivalents and marketable securities were $232.6 million as of September 30, 2025, compared to $75.0 million as of June 30, 2025. Assembly Bio’s cash position is projected to fund operations into late 2027. This cash runway guidance does not include potential future payments to Assembly Bio under the collaboration with Gilead or from potential warrant exercises, which would further extend cash runway beyond 2028. Revenue from collaborative research with Gilead was $10.8 million for the three months ended September 30, 2025, compared to $6.8 million in the same period in 2024. The change reflects the increase in research and development incurred under the collaboration as well as an increase in collaboration funding. Research and development expenses were $16.6 million for the three months ended September 30, 2025, compared to $13.5 million for the same period in 2024. The increase is largely driven by an increase in spending on the Company’s HSV program, as both ABI-1179 and ABI-5366 saw significant enrollment in their respective Phase 1b clinical studies during the current quarter. General and administrative expenses were $5.1 million for the three months ended September 30, 2025, compared to $4.3 million for the same period in 2024. The increase was primarily due to higher professional fees and increased stock-based compensation related to performance-based awards. Net loss attributable to common stockholders was $9.2 million, or $0.72 per basic and diluted share, for the three months ended September 30, 2025, compared to $9.6 million, or $1.51 per basic and diluted share, for the same period in 2024. About Assembly Biosciences Assembly Biosciences is a biotechnology company dedicated to the development of innovative small-molecule therapeutics designed to change the path of serious viral diseases and improve the lives of patients worldwide. Led by an accomplished team of leaders in virologic drug development, Assembly Bio is committed to improving outcomes for patients struggling with the serious, chronic impacts of herpesvirus, hepatitis B virus (HBV) and hepatitis delta virus (HDV) infections. 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 realize the potential benefits of its collaboration with Gilead, including all financial aspects of the collaboration and equity investments; Assembly Bio’s ability to initiate and complete clinical studies involving its therapeutic product candidates, including studies contemplated by Assembly Bio’s collaboration with Gilead, in the currently anticipated timeframes or at all; safety and efficacy data from clinical or nonclinical studies may not warrant further development of Assembly Bio’s product candidates; clinical and nonclinical data may not differentiate Assembly Bio’s product candidates from other companies’ candidates; Assembly Bio’s ability to maintain financial resources and secure additional funding necessary to continue its research activities, clinical studies, and other business operations; the U.S. federal government shutdown and potential effects of changes in government regulation, including as a result of the change in U.S. administration in 2025; 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; 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: Investors: Patrick Till Meru Advisors (484) 788-8560 [email protected] Media: Sam Brown LLC Alyssa Kuciunas (331) 481-3751 [email protected]

– 94% reduction in HSV-2 shedding rate and 98% reduction in high viral load shedding rate, both statistically significant, observed in cohort evaluating 350 mg weekly oral dose compared to placebo over 29-day evaluation period – – 94% reduction in genital lesion rate, also statistically significant, observed with 350 mg weekly oral dose compared to placebo over same period – – Favorable safety and tolerability profile observed in the first two cohorts evaluating weekly oral doses of ABI-5366 – SOUTH SAN FRANCISCO, Calif., Aug. 08, 2025 (GLOBE NEWSWIRE) -- Assembly Biosciences, Inc. (Nasdaq: ASMB), a biotechnology company developing innovative therapeutics targeting serious viral diseases, today announced positive interim antiviral activity, clinical outcomes, safety and pharmacokinetic (PK) results from a Phase 1b study evaluating ABI-5366, an investigational long-acting herpes simplex virus (HSV) helicase-primase inhibitor, in participants seropositive for HSV type 2 (HSV-2) with recurrent genital herpes. For the powered antiviral endpoint, HSV-2 shedding rate, highly potent antiviral activity was observed with a 94% reduction compared to placebo (p<0.01) over the 29-day evaluation period in the cohort evaluating a 350 mg weekly dose. This reduction exceeds Assembly Bio’s target for the study of an 80%-85% reduction in the rate of HSV-2 shedding. For a secondary clinical endpoint of genital lesion rate, a 94% reduction compared to placebo (p<0.01) was observed with the 350 mg weekly dose. The rate of samples with high viral load (i.e., >104 copies/mL HSV DNA), a potential surrogate for HSV-2 transmission and a secondary endpoint, was reduced by 98% compared to placebo (p<0.05) in this cohort. ABI-5366 was observed to be well-tolerated at oral doses up to 350 mg weekly in participants seropositive for HSV-2 with recurrent genital herpes. The observed PK profile continues to support once-weekly dosing and the potential for once-monthly oral dosing regimens. With these data, Assembly Bio expects to move directly into Phase 2 clinical study preparation in parallel with completion of this Phase 1b study, which includes an ongoing cohort evaluating a monthly oral dosing regimen. The in-life portions of chronic toxicology studies of ABI-5366 are now complete and these studies are expected to support longer-term dosing in Phase 2. “We are thrilled to see these interim data for ABI-5366 far exceeding the targets we had set in this study for antiviral activity and clinical outcomes in participants with recurrent genital herpes,” said Anuj Gaggar, MD, PhD, chief medical officer of Assembly Bio. “These results underscore our conviction in the potential for ABI-5366 to reduce outbreaks and improve quality of life for those affected by the severe impacts of recurrent genital herpes. We will now work quickly to move ABI-5366 into longer-duration Phase 2 clinical studies, which we expect to initiate in mid-2026, and look forward to its continued progress.” A Phase 1b study of ABI-1179, another long-acting HSV helicase-primase inhibitor candidate, is being conducted concurrently. Assembly Bio expects to share interim data from this study of ABI-1179 and the ongoing cohort of the ABI-5366 Phase 1b study evaluating a monthly dosing regimen in the fall of this year. Under the collaboration agreement between Assembly Bio and Gilead Sciences, Inc. (Gilead), Gilead has the right to opt in to an exclusive license for further development and commercialization of the helicase-primase inhibitor program after reviewing the option data package to be delivered by Assembly Bio following completion of the Phase 1b studies. ABI-1179 was contributed by Gilead under the collaboration between Assembly Bio and Gilead. ABI-5366 and ABI-1179 are investigational product candidates that have not been approved anywhere globally, and their safety and efficacy have not been established. Study ABI-5366-101 – Interim Phase 1b Results Interim Results The Phase 1b interim analysis reported here includes data from cohort B1, evaluating a loading dose of 150 mg and weekly doses of 30 mg (the 150/30 mg cohort), and cohort B2, evaluating a loading dose and weekly doses of 350 mg (the 350 mg cohort), through the data cutoff date of July 29, 2025. A total of 50 participants have been enrolled in the 150/30 mg and 350 mg cohorts; 40 assigned to ABI-5366 (20 participants in each cohort) and 10 assigned to placebo (five in each cohort). 45 participants from these cohorts have completed the 29-day evaluation period while five discontinued treatment; one due to an adverse event (described below), three withdrew consent and one withdrew for recurrence of genital herpes. Antiviral activity and clinical outcomes by treatment arm are summarized below. Statistically significant reductions were observed in the viral shedding rate, high viral load shedding rate and genital lesion rate for the 350 mg cohort compared to placebo as summarized below. No viral shedding of >104 HSV DNA copies/mL, a potential surrogate for HSV-2 transmission, was observed in the absence of lesions for the 350 mg cohort. Across the 150/30 mg and 350 mg cohorts, ABI-5366 demonstrated a PK profile that continues to be supportive of once-weekly and potentially once-monthly dosing. ABI-5366 was observed to be well-tolerated at oral doses up to 350 mg weekly in the study population of participants seropositive for HSV-2 with recurrent genital herpes. As the study is ongoing, individual treatment assignments remain blinded. Overall, the proportion of participants reporting treatment-emergent adverse events (TEAEs) was similar between ABI-5366 (90%) and placebo (90%) recipients. Of the TEAEs reported, the majority were grade 1 or grade 2. One grade 3 adverse event was reported, hypertriglyceridemia, in a participant with relevant medical history who had grade 4 elevated triglycerides pre-dose on Day 1. This adverse event resulted in study discontinuation but was not considered treatment related. The proportion of participants reporting treatment-emergent laboratory abnormalities was higher in placebo (90.0%) than in ABI-5366 (67.5%) recipients, with the majority of observed abnormalities being grade 1 or grade 2. There were three participants with treatment-emergent grade 3 laboratory abnormalities, all considered unrelated to assigned treatment: an exercise-associated elevation in creatine kinase, a decrease in neutrophils and an elevation of cholesterol in the follow-up period in a participant that had a grade 2 elevation at baseline. There did not appear to be a dose-response relationship in either the frequency or severity of TEAEs or laboratory abnormalities. There have been no serious adverse events reported to date. Study Overview ABI-5366-101 is a randomized, blinded, placebo-controlled Phase 1a/b clinical study of ABI-5366. Positive interim data has been previously reported for Part A (Phase 1a), evaluating the safety, tolerability and PK of ABI-5366 following single dose administration in healthy participants. Part B (Phase 1b), in participants seropositive for HSV-2 with recurrent genital herpes, is evaluating weekly and monthly oral dose regimens over a 29-day dosing period in up to four cohorts randomized 20:5 between ABI-5366 and placebo with a pooled placebo analysis. Dosing is ongoing for cohort B3, evaluating a monthly dosing regimen of ABI-5366. In addition to assessing safety, tolerability and PK, Part B also evaluates antiviral activity by measuring changes in viral parameters including shedding rate, quantification of HSV-2 DNA levels obtained from anogenital swab samples, and clinical parameters including genital lesion rate and duration. Due to the long half-life of ABI-5366, the safety follow-up period for participants extends for 98 days after dosing, with safety data available as of the data cutoff date through at least Day 56 for all participants from these cohorts that completed the evaluation period. The trial results will support dose selection for future clinical studies. The ABI-5366 Phase 1b study uses pooled data from placebo recipients across cohorts as a control. As additional placebo recipients are enrolled in later cohorts, the sample size for the pooled placebos will change, which is expected to result in adjustments to both the observed effect sizes compared to placebo and the tests of statistical significance for those observed effects. Additional information about the Phase 1a/b trial is available at clinicaltrials.gov using the identifier NCT06385327. Assembly Bio expects to submit data from the trial for presentation at future scientific meetings. About Recurrent Genital Herpes Genital herpes is a chronic viral infection caused by HSV that can result in painful genital lesions, serious psychological and social impacts, and an increased risk of acquiring human immunodeficiency virus (HIV). Epidemiologic studies estimate over four million people in the United States and France, Germany, Italy, Spain and the United Kingdom experience recurrent genital herpes, with most people with initial symptomatic genital HSV-2 infection having three or more recurrences per year. While genital herpes can be caused by either HSV type 1 (HSV-1) or HSV-2, recurrences are more likely to be experienced by individuals infected by HSV-2. The current standard of care for recurrent genital herpes is nucleoside analogs given intermittently for recurrences or as daily chronic suppressive therapy; however, these are only partially effective in preventing recurrences and in reducing transmission of the virus. No new drugs have been approved in the United States or Europe to treat genital herpes for more than 25 years. About Helicase-Primase Inhibition HSV helicase-primase inhibitors target the viral helicase-primase complex, an essential viral enzyme complex that is conserved across both HSV-1 and HSV-2 and has no host equivalent. Inhibition of the helicase-primase complex is a clinically validated mechanism that has shown the potential for superior efficacy to the current standard of care, nucleoside analogs, in short-duration clinical studies in participants with recurrent genital herpes. About Assembly Biosciences Assembly Biosciences is a biotechnology company dedicated to the development of innovative small-molecule therapeutics designed to change the path of serious viral diseases and improve the lives of patients worldwide. Led by an accomplished team of leaders in virologic drug development, Assembly Bio is committed to improving outcomes for patients struggling with the serious, chronic impacts of herpesvirus, hepatitis B virus (HBV) and hepatitis delta virus (HDV) infections. 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 maintain financial resources and secure additional funding necessary to continue its research activities, clinical studies, other business operations and continue as a going concern; Assembly Bio’s ability to realize the potential benefits of its collaboration with Gilead, including all financial aspects of the collaboration and equity investments; Assembly Bio’s ability to initiate and complete clinical studies involving its therapeutic product candidates, including studies contemplated by Assembly Bio’s collaboration with Gilead, in the currently anticipated timeframes or at all; safety and efficacy data from clinical or nonclinical studies may not warrant further development of Assembly Bio’s product candidates; clinical and nonclinical data may not differentiate Assembly Bio’s product candidates from other companies’ candidates; potential effects of changes in government regulation, including as a result of the change in U.S. administration in 2025; 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; 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: Shannon Ryan SVP, Investor Relations, Corporate Affairs and Alliance Management (415) 738-2992 [email protected] Media: Sam Brown Healthcare Communications Alyssa Kuciunas (331) 481-3751 [email protected]