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.