Key Takeaways GILD will exclusively license and advance ASMB's HSV candidates ABI-1179 & ABI-5366 for genital herpes.Interim data on ABI-1179 & ABI-5366 showed strong antiviral activity and reduced virus-positive lesions.ASMB will receive $35M upfront and may earn up to $330M in milestones plus tiered royalties on sales.Gilead Sciences (GILD) recently announced that it has exercised its combined option to exclusively license Assembly Biosciences’ (ASMB) herpes simplex virus (HSV) helicase-primase inhibitor ...

Core Insights - Biotechnology stocks experienced significant movements in after-hours trading, with several companies reporting strong gains driven by positive trial results and strategic announcements [1] Company Performances - Exicure, Inc. (XCUR) saw a substantial increase of 72.61% to $9.20 after announcing positive Phase 2 trial results for burixafor, achieving a primary endpoint success rate of approximately 90% in multiple myeloma patients [2] - Artiva Biotherapeutics, Inc. (ARTV) rose 10.39% to $3.40 despite a regular session decline, with no new updates reported [3] - iBio, Inc. (IBIO) advanced 8.38% to $1.81, following a significant 39.17% increase during regular trading [3] - Cartesian Therapeutics, Inc. (RNAC) increased by 6.55% to $7.16, recovering from a prior decline [4] - Metagenomi, Inc. (MGX) gained 7.18% to $1.94, with plans to present preclinical data at an upcoming conference [5] - BioAtla, Inc. (BCAB) rose 4.81% to $0.85, despite no new updates [6] - ProMIS Neurosciences, Inc. (PMN) climbed 3.02% to $7.85, following a publication related to Alzheimer's disease biomarkers [7] - DiaMedica Therapeutics Inc. (DMAC) increased by 4.77% to $9.18, with no new announcements [8] - Wave Life Sciences Ltd. (WVE) shares surged 4.97% to $19.44 after a significant 147.26% increase during regular trading, linked to a $250 million public offering [9] - Assembly Biosciences, Inc. (ASMB) gained 5.96% to $37.49, reporting positive interim results from Phase 1b studies of HSV inhibitors [10]

Core Insights - The company has reported impressive results from Phase Ib clinical studies of its long-acting helicase-primase inhibitor candidates, ABI-1179 and ABI-5366, for treating recurrent genital herpes [3]. Group 1: Clinical Study Results - Both ABI-1179 and ABI-5366 met or exceeded all key objectives of the study, indicating a significant advancement in treatment options for individuals with recurrent genital herpes [3]. - The data suggests a potential path to a best-in-class therapy, particularly in terms of dosing interval and improved efficacy compared to currently approved agents [3].

Summary of Assembly Biosciences Conference Call - December 08, 2025 Company Overview - **Company**: Assembly Biosciences (NasdaqGS: ASMB) - **Focus**: Development of long-acting helicase-primase inhibitors for the treatment of recurrent genital herpes Key Points Clinical Study Results - **Phase 1b Clinical Studies**: Results from two long-acting helicase-primase inhibitor candidates, ABI-1179 and ABI-5366, were presented, showing significant efficacy in reducing HSV-2 shedding and lesions in participants with recurrent genital herpes [2][3][4] - **ABI-5366 Results**: - 94% reduction in HSV-2 shedding and 97% reduction in virologically confirmed lesions in cohort B2 [3] - Monthly dosing cohort B3 showed potent antiviral activity but indicated the need for further optimization to maintain suppression levels [4][5] - **ABI-1179 Results**: - 98% reduction in HSV shedding and 92% reduction in lesions in cohort B1 [4][10] - Overall, ABI-1179 met or exceeded established goals with significant reductions in viral shedding and lesions compared to placebo [13] Safety and Tolerability - **Safety Profile**: Both ABI-1179 and ABI-5366 were well tolerated with no serious adverse events reported. Most treatment-emergent adverse events were Grade one or two [9][17] - **Adverse Events**: A single Grade three adverse event (migraine) was reported in ABI-1179, with no treatment discontinuations due to adverse events [9][17] Efficacy Metrics - **Efficacy Goals**: The target for the studies was an 80%-85% reduction in HSV-2 shedding, which was exceeded by both candidates [10][18] - **High Viral Load Shedding**: Near complete elimination of high viral load shedding was observed, with a greater than 99% reduction for the 50 mg dose of ABI-1179 [11][20] - **Virologically Confirmed Lesions**: For ABI-1179, a 91% reduction in lesions was noted for the 50 mg dose compared to placebo [12][21] Future Development Plans - **Next Steps**: Plans to initiate a phase 2 clinical study for ABI-5366 in mid-2026, with ongoing preparations for ABI-1179 [24][25] - **Collaboration with Gilead Sciences**: Gilead has the option to opt into an exclusive license for the HSV program, with ongoing discussions regarding the phase 1b datasets [25] Financial Position - **Cash Runway**: The company has a strong financial foundation, expecting to fund operations into late 2027, excluding potential future payments from collaborations [26] Market Potential - **Therapeutic Paradigm Shift**: Both ABI-5366 and ABI-1179 are believed to have the potential to change the treatment landscape for recurrent genital herpes, offering improved efficacy and convenience over current standard treatments [24][23] Additional Insights - **Formulation Optimization**: The company is exploring formulation tweaks to enhance exposure levels for ABI-5366, with a focus on long-term life cycle management [30][33] - **Regulatory Considerations**: Discussions with regulators will be necessary to incorporate high viral load shedding as a surrogate for transmission reduction in future studies [55][56] This summary encapsulates the critical findings and future directions for Assembly Biosciences as discussed in the conference call.

Interim Results from Phase 1b Clinical Studies of Long-Acting Helicase-Primase Inhibitor Candidates ABI-1179 and ABI-5366 in Recurrent Genital Herpes December 8, 2025 Nasdaq: ASMB ©2025 ASSEMBLY BIOSCIENCES, INC. 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 re ...

Summary of Assembly Biosciences FY Conference Call Company Overview - **Company**: Assembly Biosciences (NasdaqGS: ASMB) - **Focus**: Originally a capsid assembly modulator company targeting Hepatitis B Virus (HBV), now expanded to include herpes virus treatments, particularly for recurrent genital herpes [3][4] Recent Developments - **Pipeline Expansion**: The company has developed two lead compounds for recurrent genital herpes, 5366 and 1179, both currently in phase 1b trials [3][4] - **Positive Data**: Recently announced positive interim data for 5366, showing significant efficacy in reducing viral shedding and lesions [10][12][13] Market Opportunity - **Unmet Need**: There is a significant unmet need in the genital herpes market, with the last treatment approval nearly 20 years ago. Many patients experience multiple recurrences annually, and current treatments are inadequate [5][6] - **Patient Population**: Focus on patients with three to ten lesions per year, who often rely on daily suppressive therapy with valacyclovir, which has a high failure rate [5][6] Product Details - **5366**: A helicase-primase inhibitor, 400 times more potent than valacyclovir, with a 20-day half-life, designed for long-acting oral or injectable use [8][9] - **1179**: Discovered at Gilead, approximately 1,000 times more potent than valacyclovir, with a four-day half-life, supporting potential once-a-week treatment [8][9] Clinical Data Highlights - **Efficacy Results**: In the phase 1b trial for 5366, there was over a 90% reduction in shedding rates and a 98% reduction in high viral load swabs compared to placebo. Additionally, there was a greater than 90% reduction in lesions [12][13] - **Safety Data**: Upcoming unblinded safety data for 5366 will be shared in December, with expectations of confirming its well-tolerated profile [17][22] Future Plans - **Phase 2 Trials**: Plans to conduct head-to-head trials against valacyclovir, focusing on longer duration studies to evaluate efficacy and safety [26][31] - **Market Potential**: Estimated market size for recurrent genital herpes treatment in the U.S. is around 1.3-1.4 million patients, with over 800,000 on chronic suppressive therapy, indicating a multi-billion dollar market opportunity [33] Additional Programs - **Hepatitis Delta**: Development of an oral small molecule (6250) targeting the same mechanism as Gilead's Bulevirtide, with promising phase 1 results [36][39] - **Hepatitis B**: Ongoing development of a capsid assembly modulator (4334) with high antiviral effects, awaiting Gilead's review for potential opt-in [42][43] Financial Position - **Cash Reserves**: The company reported a cash position of over $230 million, expected to last until at least the end of 2027, with additional contributions from Gilead anticipated [43][44] Conclusion - **Strategic Collaboration**: The partnership with Gilead provides optionality for advancing both HSV and HBV programs, with a focus on bringing effective treatments to market quickly [44]

Clinical Development - The company is developing multiple clinical-stage investigational therapies targeting serious viral diseases, including two helicase-primase inhibitors (HPIs) for recurrent genital herpes and an orally bioavailable hepatitis delta virus (HDV) entry inhibitor[74]. - Interim results from the Phase 1b study of the HPI ABI-5366 showed a 94% reduction in HSV-2 shedding rate compared to placebo over a 29-day evaluation period with a 350 mg weekly dose[86]. - The Phase 1a study of ABI-5366 demonstrated a mean half-life of approximately 20 days, supporting potential once-weekly or once-monthly oral dosing regimens[84]. - The company has initiated both Phase 1a and Phase 1b studies for ABI-1179, another long-acting HPI, with positive interim data reported in February 2025[92]. - Enrollment for the Phase 1b portion of the ABI-5366 study is complete, with plans to move directly into Phase 2 clinical study preparation[89]. - The company plans to report interim data on two cohorts of weekly dosing of ABI-1179 and one cohort of monthly dosing of ABI-5366 by the end of 2025[94]. - The company is preparing for Phase 2 clinical studies for 6250 following the completion of the Phase 1a study[110]. Hepatitis B and D Virus Programs - The World Health Organization estimates that 254 million people are chronically infected with HBV, with only 3% of diagnosed patients receiving treatment[95]. - Current standard care for chronic HBV infection has not seen new mechanisms of action approved in over 25 years, highlighting the need for innovative therapies[96]. - The company is advancing its HBV program to improve patient outcomes and increase the number of patients diagnosed and treated through finite and curative therapies[97]. - HDV affects approximately 12 to 72 million HBV-infected individuals, accounting for 18% of cirrhosis and 20% of hepatocellular carcinoma associated with HBV[98]. - The novel small molecule entry inhibitor 6250 demonstrated low nanomolar potency against all tested HBV/HDV genotypes and good oral bioavailability, supporting once-daily dosing[103]. - In Phase 1a studies, 6250 showed a mean half-life of approximately four days, with exposures on the last day of dosing reaching six- to seven-fold higher than after the first dose[105]. - The 150 mg and 400 mg cohorts of the next-generation capsid assembly modulator 4334 observed mean declines in HBV DNA of 2.9 log10 IU/mL and 3.2 log10 IU/mL over 28 days, respectively[115]. - The first therapy approved for HDV, bulevirtide, is currently only available in Europe, highlighting the need for new treatments[99]. - The company has identified a development candidate, ABI-7423, in its broad-spectrum NNPI program targeting transplant-associated herpesviruses, transitioning to its parent molecule ABI-7272 for further studies[77]. Financial Performance - Collaboration revenue for the three months ended September 30, 2025, was $10.8 million, a 58% increase from $6.8 million in the same period in 2024, primarily due to higher costs incurred under the Gilead Collaboration Agreement[129]. - Research and development expenses for the three months ended September 30, 2025, totaled $16.6 million, up 23% from $13.5 million in 2024, driven by increased external program expenses and higher employee-related costs[133]. - General and administrative expenses increased by 19% to $5.1 million for the three months ended September 30, 2025, compared to $4.3 million in 2024, mainly due to higher professional fees and stock-based compensation[136]. - Interest and other income, net, was $1.7 million for the three months ended September 30, 2025, reflecting a 26% increase from $1.3 million in 2024, attributed to higher interest earned on marketable securities[137]. - For the nine months ended September 30, 2025, collaboration revenue reached $29.8 million, a 41% increase from $21.2 million in 2024, due to increased costs under the Gilead Collaboration Agreement[138]. - Total research and development expenses for the nine months ended September 30, 2025, were $47.6 million, a 14% increase from $41.7 million in 2024, driven by higher external program expenses related to ongoing clinical studies[141]. - External program expenses for the 5366 program increased by 82% to $7.2 million for the nine months ended September 30, 2025, compared to $3.9 million in 2024[139]. - General and administrative expenses increased to $14.2 million for the nine months ended September 30, 2025, up from $13.4 million in 2024, representing a 6% increase[142]. - Interest and other income, net decreased to $3.7 million for the nine months ended September 30, 2025, down from $4.5 million in 2024, a decline of 17%[144]. - Net cash used in operating activities was $55.3 million for the nine months ended September 30, 2025, compared to $50.7 million in 2024, indicating increased operational expenses[148]. - Net cash used in investing activities was $134.7 million for the nine months ended September 30, 2025, compared to net cash provided of $46.9 million in 2024, primarily due to purchases of marketable securities[149]. - Net cash provided by financing activities was $174.2 million for the nine months ended September 30, 2025, significantly higher than $12.5 million in 2024, due to larger proceeds from financing transactions[150]. - As of September 30, 2025, the company had an accumulated deficit of $854.1 million, with expectations of continued losses as product candidates are developed[151]. - The company held cash, cash equivalents, and marketable securities of $232.6 million as of September 30, 2025, with sufficient funds projected to meet operating requirements into late 2027[152]. - The company raised an aggregate of $821.8 million in net proceeds from equity financings and $200.9 million from strategic collaborations since incorporation[145]. - In August 2025, the company raised approximately $166.4 million from a financing transaction involving the sale of 5,591,840 shares of common stock and warrants[146]. - Future capital requirements will depend on various factors, including the progress of drug development and regulatory reviews[154]. Collaboration with Gilead - Gilead made an upfront cash payment of $84.8 million as part of the collaboration agreement, with potential regulatory and commercial milestones up to $330 million per program[121][122]. - The opt-in fee for Gilead to exercise its rights ranges from $45 million to $125 million per program, depending on the clinical stage[121]. - Gilead made an upfront equity investment of $15.2 million by purchasing 1,089,472 shares at $13.92 per share, with an option to purchase additional shares to reach 29.9% ownership[125]. - Gilead's participation in the August 2025 financing transaction included the purchase of 2,295,920 shares at $19.60 per share, along with warrants for additional shares[127]. - The company filed a Registration Statement on Form S-3 with the SEC to register shares issued to Gilead, as required under the Investor Rights Agreement[128].

Financial Performance - Assembly Biosciences reported a net loss of $9.2 million, or $0.72 per share, for Q3 2025, compared to a net loss of $9.6 million, or $1.51 per share, in Q3 2024[12]. - Cash, cash equivalents, and marketable securities totaled $232.6 million as of September 30, 2025, compared to $75.0 million as of June 30, 2025, providing a cash runway projected to fund operations into late 2027[8]. - Assembly Biosciences raised $175 million in gross proceeds from equity financing, enhancing its financial position to support ongoing and future clinical development[3]. - Research and development expenses increased to $16.6 million for Q3 2025, compared to $13.5 million in Q3 2024, primarily due to spending on the HSV program[12]. - Total operating expenses for Q3 2025 were $21.7 million, up from $17.8 million in the same period in 2024[12]. Research and Development - Revenue from collaborative research with Gilead was $10.8 million for Q3 2025, up from $6.8 million in the same period in 2024, reflecting increased research and development activities[12]. - Positive interim results were released from the Phase 1b study of ABI-5366, showing significant reductions in HSV-2 shedding and genital lesion rates in participants with recurrent genital herpes[4]. - Enrollment was completed in the ongoing Phase 1b studies for both ABI-5366 and ABI-1179, with additional data updates expected by the end of the year[4]. - The Phase 1a study of ABI-6250 demonstrated a pharmacokinetic profile supporting once-daily dosing, leading to its progression into Phase 2 evaluation[9]. - The initiation of a Phase 2 clinical study of ABI-5366 is anticipated in mid-2026[9].

Core Insights - Assembly Biosciences, Inc. reported significant progress in its clinical pipeline, particularly with positive interim results for its long-acting helicase-primase inhibitor candidate ABI-5366 in recurrent genital herpes [1][3] - The company raised $175 million in gross proceeds from equity financing, enhancing its financial position to support ongoing and future clinical developments [1][13] Herpes Simplex Virus (HSV) Developments - Positive Phase 1b interim results for ABI-5366 showed significant reductions in viral shedding and genital lesion rates in participants with recurrent genital herpes [1][7] - Enrollment in the Phase 1b study for ABI-5366 and two cohorts for ABI-1179 has been completed, with additional data expected by the end of the year [1][3][7] Hepatitis D Virus (HDV) Developments - Interim results from a Phase 1a study of ABI-6250, an oral HDV entry inhibitor, support progression to Phase 2 evaluation [1][7] - The pharmacokinetic profile of ABI-6250 indicates potential for once-daily dosing, with dose-dependent increases in a biomarker of target engagement [1][7] Financial Performance - Cash, cash equivalents, and marketable securities totaled $232.6 million as of September 30, 2025, compared to $75.0 million as of June 30, 2025, providing a cash runway into late 2027 [13] - Revenue from collaborative research with Gilead was $10.8 million for the three months ended September 30, 2025, an increase from $6.8 million in the same period in 2024 [13] - Research and development expenses rose to $16.6 million for the third quarter of 2025, up from $13.5 million in the same period in 2024, primarily due to increased spending on the HSV program [13]

Core Insights - Assembly Biosciences, Inc. announced positive Phase 1b clinical data for its investigational capsid assembly modulator ABI-4334, showcasing a favorable safety profile and significant reductions in viral nucleic acids [1][2][3] Group 1: Clinical Data - The Phase 1b study involved two cohorts of predominantly HBeAg-negative subjects, evaluating 150 mg and 400 mg oral doses of ABI-4334 administered once daily for 28 days [3] - ABI-4334 demonstrated well-tolerated results at both dose levels, with multi-log declines in hepatitis B virus (HBV) DNA and pregenomic RNA (pgRNA) observed, indicating effective suppression of viral replication [3] - The study results support the potential of ABI-4334 to maximize antiviral activity as part of multi-drug combination regimens targeting chronic hepatitis B infection [2][3] Group 2: Presentation and Collaboration - The complete Phase 1b data was presented in a late-breaking poster at the American Association for the Study of Liver Diseases (AASLD) conference, marking the first scientific presentation of these findings [1][2] - Under a collaboration agreement with Gilead Sciences, Gilead has the option to obtain an exclusive license for further development and commercialization of ABI-4334 after reviewing the data package post-Phase 1b study [4]