Assembly Biosciences (ASMB) 3rd Annual Guggenheim Healthcare Innovation Conference summary

Execution and outlook

• 2026 framed as an execution year after a data-heavy 2025; major new data expected from H2 2027 into 2028.

• Opted into a 40/60 cost-profit share with Gilead for HSV-2; Gilead is also exploring a potential dual HIV/HSV PrEP approach.

• Cash was ~$320 million as of the prior quarter, excluding $75 million in Gilead extension fees; runway expected well into 2029.

• Potential financing after data readouts would support phase III development and the 40% HSV-2 profit share.

HSV-2 program

• Recurrent genital herpes market estimated at $2 billion+ excluding dual PrEP; U.S. patient estimate of 1.3–1.4 million, including ~800,000 on chronic Valtrex therapy.

• ABI-1179 is expected to offer greater efficacy and once-weekly dosing versus Valtrex; payer testing indicated potential pricing above Valtrex’s ~$5,500 brand price, in a $5,500–$10,000 range.

• Gilead’s phase II GS-1179 trial compares high and low doses with Valtrex in patients with 4–9 annual recurrences; viral shedding is the primary endpoint, with lesion measures among secondary endpoints.

• Phase II is intended to benchmark against Valtrex, select a dose, and inform phase III; Gilead controls the program and data were hoped for in 2027.

• Gilead’s dual PrEP exploration is potential upside; economics depend on GS-1179’s contribution, with Assembly receiving 40% of that portion under the cost-profit arrangement.

ABI-6250 for hepatitis D

• ABI-6250 is an oral NTCP inhibitor targeting the HBV/HDV entry receptor; the target is clinically validated by bulevirtide, whose daily injection and refrigeration are burdensome.

• Phase I showed a four-day half-life and dose-dependent peripheral bile-acid increases; biomarker effects matched or exceeded bulevirtide levels, informing phase II dose selection.

• Phase II compares low dose, high dose, and delayed treatment over 16 weeks; follow-up continues through week 48, with an expansion cohort to support phase III planning.

• H2 2027 is the expected window for the first phase II dataset; dose selection will weigh antiviral effect and safety.

• Mirum and Vir phase III composite responses were described as ~50%, similar to bulevirtide; ABI-6250 aims to differentiate as an oral small molecule versus injectable competitors.