Assembly Biosciences Officer Sells Shares for Tax Withholding

Jeanette M. Bjorkquist, Principal Financial Officer and Principal Accounting Officer of Assembly Biosciences, Inc., sold 29 shares of common stock on June 17, 2026, at $23.25 per share. The sale was conducted to cover tax withholding obligations related to the vesting and settlement of restricted stock units. This was a mandatory "sell-to-cover" transaction required by the Compensation Committee's administrative rule, not a discretionary sale by the officer. Following the transaction, Bjorkquist retains 14,560 shares of Assembly Biosciences common stock. The filing was signed by attorney-in-fact John O. Gunderson on June 18, 2026.