Assembly Biosciences (ASMB) Guggenheim Securities 2nd Annual Healthcare Innovation Conference summary

Pipeline overview and recent developments

• Expanded from HBV focus to a broader herpes virus pipeline, with two lead compounds (5366 and 1179) in phase 1b for recurrent genital herpes and additional assets in hepatitis delta and HBV in clinical stages.

• 5366 and 1179 are both highly potent, long-acting molecules, with 5366 showing a 20-day half-life and 1179 a four-day half-life, supporting once-weekly dosing.

• Positive interim data for 5366 showed over 90% reduction in viral shedding and lesions, with statistically significant results and strong safety profile.

• Upcoming data releases in December will include unblinded safety data for 5366 and initial efficacy and safety data for 1179.

• Phase 2 trials are planned to start mid-2026, with head-to-head studies against Valtrex and dose selection guided by PK/PD modeling.

Market opportunity and competitive landscape

• Recurrent genital herpes remains inadequately treated, with current standard of care (valacyclovir) requiring daily dosing and only one-third of patients lesion-free for a year.

• Once-weekly, more potent therapies could command a moderate premium over Valtrex, with a target market of over 1.3 million U.S. patients on chronic suppressive therapy.

• Both 5366 and 1179 are being positioned for chronic suppressive therapy, with potential for monthly or injectable formulations and expansion into HSV-1 and episodic use.

• Head-to-head data suggest the new compounds may outperform current and emerging competitors on both viral shedding and lesion reduction.

Additional programs and partnerships

• Hepatitis delta program (6250) targets the same mechanism as bulevirtide but as a once-daily oral, showing strong safety, PK, and target engagement in phase 1a.

• HBV program (4334) demonstrated high antiviral effect in phase 1b, with data under review by Gilead for potential opt-in.

• Gilead partnership provides financial runway through at least 2027 and optionality for further development and commercialization, with opt-in decisions pending for HBV and HSV-2 assets.