X0306 4 2022-08-08 0 0001426800 ASSEMBLY BIOSCIENCES, INC. ASMB 0001738125 McHutchison John G C/O ASSEMBLY BIOSCIENCES, INC. 331 OYSTER POINT BLVD., FOURTH FLOOR SOUTH SAN FRANCISCO CA 94080 1 1 0 0 Chief Executive Officer Common Stock 2022-08-08 4 S 0 12314 2.1277 D 192515 D The sale reported on this Form 4 was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person and represents shares sold to cover tax withholding obligations in connection with the vesting of restricted stock units. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $2.08 to $2.21, inclusive. The reporting person undertakes to provide the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within. /s/ John O. Gunderson, as Attorney-in-Fact 2022-08-10