Delaney William E IV

SEC source: 0001193125-26-134554 · ownership.xml · nonDerivative · entry 1

Delaney William E IV · CIK 0001812734 · Chief Scientific Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 45,642

F1 · shares: Grant of restricted stock units ("RSUs"). The RSUs vest in four equal installments, assuming continuous service on each vesting date, as follows: March 29, 2027; March 29, 2028; March 29, 2029; and March 29, 2030.

F2 · shares: RSUs represent 65% of the reporting person's annual equity grant. The remaining 35% of the RSUs granted are contingent upon stockholder approval of an amendment to the Issuer's Amended and Restated 2018 Stock Incentive Plan (the "Plan") that increases the number of shares of common stock authorized for issuance under the Plan.

F3 · balance_after: Includes 2,909 shares acquired under the Assembly Biosciences, Inc. Second Amended and Restated 2018 Employee Stock Purchase Plan on May 14, 2025.

SEC source: 0001193125-26-259562 · ownership.xml · nonDerivative · entry 1

Delaney William E IV · CIK 0001812734 · Chief Scientific Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 60,330

F1 · shares: Restricted stock units ("RSUs") representing 35% of the reporting person's annual equity grant, which was approved on March 29, 2026 and was contingent upon stockholder approval of an amendment to the Issuer's Amended and Restated 2018 Stock Incentive Plan (the "Plan") that increased the number of shares of common stock authorized for issuance under the Plan (the "Plan Amendment"). Although the RSUs were granted on March 29, 2026, the RSUs became issuable upon stockholder approval of the Plan Amendment on June 4, 2026 and vest in four approximately equal installments, assuming continuous service on each vesting date, as follows: March 29, 2027; March 29, 2028; March 29, 2029; and March 29, 2030.

F2 · balance_after: Includes 688 shares acquired under the Assembly Biosciences, Inc. Second Amended and Restated 2018 Employee Stock Purchase Plan on May 14, 2026.

SEC source: 0000950170-25-048488 · ownership.xml · derivative · entry 2

Delaney William E IV · CIK 0001812734 · Chief Scientific Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 25,500

Underlying: Common Stock · 25,500 shares

Expires 2035-03-29

F2 · derivative.exercise_date: Grant of stock options. The stock options vest over four years, assuming continuous service on each vesting date, as follows: 25% vest on the first anniversary of the date of grant, March 29, 2026; and the remaining 75% vest in 36 approximately equal monthly installments, with the options becoming fully vested on March 29, 2036.

SEC source: 0000950170-24-051243 · ownership.xml · nonDerivative · entry 1

Delaney William E IV · CIK 0001812734 · Chief Scientific Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 16,109

F1 · kind: Represents shares of common stock issuable under a performance-based restricted stock unit award dated August 1, 2022. On April 29, 2024, a performance-based vesting condition was achieved.

F2 · balance_after: Reflects equitable adjustment of the number of shares beneficially owned by the reporting person resulting from a 1-for-12 reverse stock split of the Issuer's common stock effected February 9, 2023, which is exempt from reporting pursuant to Rule 16a-9.

SEC source: 0000950170-24-040149 · ownership.xml · derivative · entry 1

Delaney William E IV · CIK 0001812734 · Chief Scientific Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 20,000

Underlying: Common Stock · 20,000 shares

Expires 2034-03-29

F1 · derivative.exercise_date: Grant of stock options. The stock options vest over four years, assuming continuous service on each vesting date, as follows: 25% vest on the first anniversary of the date of grant, March 29, 2025; and the remaining 75% vest in 36 approximately equal monthly installments, with the options becoming fully vested on March 29, 2028.

SEC source: 0001209191-23-051910 · doc4.xml · nonDerivative · entry 2

Delaney William E IV · CIK 0001812734 · Chief Scientific Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 150,853

F2 · kind: The sale reported on this Form 4 represents shares sold by the reporting person to cover tax withholding obligations in connection with the vesting and settlement of restricted stock units. The sale is mandated by an administrative rule adopted by the Compensation Committee of the Issuer's Board of Directors that requires the satisfaction of tax withholding obligations to be funded by a "sell-to-cover" transaction and does not represent a discretionary transaction by the reporting person.

F3 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $0.79 to $0.83, 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.

SEC source: 0001209191-23-051910 · doc4.xml · nonDerivative · entry 1

Delaney William E IV · CIK 0001812734 · Chief Scientific Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 152,744

F1 · shares: Represents shares of common stock issuable under a performance-based restricted stock unit award dated August 1, 2022. On October 2, 2023, a performance-based vesting condition was achieved. These shares of common stock vest in two equal installments, assuming continuous service on each vesting date, as follows: October 2, 2023 and October 2, 2024.

SEC source: 0001209191-23-044405 · doc4.xml · nonDerivative · entry 1

Delaney William E IV · CIK 0001812734 · Chief Scientific Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 142,744

F1 · kind: The sale reported on this Form 4 represents shares sold by the reporting person to cover tax withholding obligations in connection with the vesting and settlement of restricted stock units. The sale is mandated by an administrative rule adopted by the Compensation Committee of the Issuer's Board of Directors that requires the satisfaction of tax withholding obligations to be funded by a "sell-to-cover" transaction and does not represent a discretionary transaction by the reporting person.

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $1.0801 to $1.10, 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.

SEC source: 0001209191-23-039532 · doc4.xml · nonDerivative · entry 1

Delaney William E IV · CIK 0001812734 · Chief Scientific Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 152,205

F1 · shares: Represents shares of common stock issuable under a performance-based restricted stock unit award dated August 1, 2022. On June 22, 2023, a performance-based vesting condition was achieved with respect to these shares of common stock, which remain subject to time-based vesting and will vest in two equal installments, assuming continuous service on each vesting date, as follows: August 1, 2023 and August 1, 2024.

SEC source: 0001209191-23-033100 · doc4.xml · nonDerivative · entry 1

Delaney William E IV · CIK 0001812734 · Chief Scientific Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 112,205

F1 · kind: The sale reported on this Form 4 represents shares sold by the reporting person to cover tax withholding obligations in connection with the vesting and settlement of restricted stock units. The sale is mandated by an administrative rule adopted by the Compensation Committee of the Issuer's Board of Directors that requires the satisfaction of tax withholding obligations to be funded by a "sell-to-cover" transaction and does not represent a discretionary transaction by the reporting person.

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $0.9532 to $0.97, 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.

SEC source: 0001209191-23-031912 · doc4.xml · nonDerivative · entry 2

Delaney William E IV · CIK 0001812734 · Chief Scientific Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 116,437

F3 · kind: The sale reported on this Form 4 represents shares sold by the reporting person to cover tax withholding obligations in connection with the vesting and settlement of restricted stock units. The sale is mandated by an administrative rule adopted by the Compensation Committee of the Issuer's Board of Directors that requires the satisfaction of tax withholding obligations to be funded by a "sell-to-cover" transaction and does not represent a discretionary transaction by the reporting person.

F4 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $1.02 to $1.07, 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.

SEC source: 0001209191-23-031912 · doc4.xml · nonDerivative · entry 1

Delaney William E IV · CIK 0001812734 · Chief Scientific Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 122,998

F1 · shares: Represents shares of common stock issuable under a performance-based restricted stock unit award dated July 22, 2021. On May 22, 2023, the performance-based vesting conditions were achieved. These shares of common stock vest in two equal installments, assuming continuous service on each vesting date, as follows: May 22, 2023 and May 22, 2024.

F2 · balance_after: Includes 2,500 shares acquired under the Assembly Biosciences, Inc. Amended and Restated 2018 Employee Stock Purchase Plan on May 12, 2023.

SEC source: 0001209191-23-021874 · doc4.xml · nonDerivative · entry 1

Delaney William E IV · CIK 0001812734 · Chief Scientific Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 85,498

F1 · kind: The sale reported on this Form 4 represents shares sold by the reporting person to cover tax withholding obligations in connection with the vesting and settlement of Restricted Stock Units ("RSUs"). The sale is mandated by an administrative rule adopted by the Compensation Committee of the Issuer's Board of Directors that requires the satisfaction of tax withholding obligations to be funded by a "sell-to-cover" transaction and does not represent a discretionary transaction by the reporting person.

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $0.7795 to $0.89, 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.

SEC source: 0001209191-23-021874 · doc4.xml · derivative · entry 2

Delaney William E IV · CIK 0001812734 · Chief Scientific Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 140,000

Underlying: Common Stock · 140,000 shares

Expires 2033-03-29

F3 · derivative.exercise_date: Grant of stock options. The stock options vest over four years, assuming continuous service on each vesting date, as follows: 25% vest on the first anniversary of the date of grant, March 29, 2024; and the remaining 75% vest in 36 approximately equal monthly installments, with the options becoming fully vested on March 29, 2027.

SEC source: 0001209191-23-010529 · doc4.xml · nonDerivative · entry 1

Delaney William E IV · CIK 0001812734 · Chief Scientific Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 88,919

F1 · shares: Represents shares of common stock issuable under a performance-based restricted stock unit award dated August 1, 2022. On February 16, 2023, a performance-based vesting condition was achieved with respect to these shares of common stock, which remain subject to time-based vesting and will vest in two equal installments, assuming continuous service on each vesting date, as follows: August 1, 2023 and August 1, 2024.

F2 · balance_after: Includes 2,500 shares acquired under the Assembly Biosciences, Inc. Amended and Restated 2018 Employee Stock Purchase Plan on November 14, 2022.

SEC source: 0001209191-22-044274 · doc4.xml · derivative · entry 1

Delaney William E IV · CIK 0001812734 · Chief Scientific Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 200,000

Underlying: Common Stock · 200,000 shares

Expires 2032-08-01

F1 · derivative.exercise_date: Grant of stock options. The stock options vest over four years, assuming continuous service on each vesting date, as follows: 25% vest on the first anniversary of the date of grant, August 1, 2022; and the remaining 75% vest in 36 approximately equal monthly installments, with the options becoming fully vested on August 1, 2026.

SEC source: 0001209191-22-033582 · doc4.xml · nonDerivative · entry 1

Delaney William E IV · CIK 0001812734 · Chief Scientific Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 76,419

F1 · kind: 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.

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $1.88 to $1.95, 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.

F3 · balance_after: Includes 2,500 shares acquired under the Assembly Biosciences, Inc. Amended and Restated 2018 Employee Stock Purchase Plan on May 13, 2022.

SEC source: 0001209191-22-021774 · doc4.xml · nonDerivative · entry 2

Delaney William E IV · CIK 0001812734 · Chief Scientific Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 78,083

F3 · kind: 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.

F4 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $2.10 to $2.25, 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.

SEC source: 0001209191-22-021774 · doc4.xml · derivative · entry 4

Delaney William E IV · CIK 0001812734 · Chief Scientific Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 25,000

Underlying: Common Stock · 25,000 shares

Expires 2027-03-29

F6 · derivative.exercise_price: Each performance-based restricted stock unit ("RSU") represents a contingent right to receive one share of the Issuer's common stock. The shares are earned if either of two trading price metrics are met (each a "Stock Metric") either on or before the second or on or before the fourth anniversary of the grant date, as applicable. If a Stock Metric is met on or before the first anniversary of the grant date, then 50% of the RSUs vest on the first anniversary of the grant date and the remainder will vest on the second anniversary of the grant date. If a Stock Metric is achieved after the first anniversary of the grant date and on or before the fourth anniversary of the grant date, then 50% of the RSUs vest on the date that the Stock Metric is achieved and the remaining 50% of the RSUs vest on the first anniversary of the initial vesting date. Special vesting provisions apply in the case of a change in control transaction.

F6 · derivative.exercise_date: Each performance-based restricted stock unit ("RSU") represents a contingent right to receive one share of the Issuer's common stock. The shares are earned if either of two trading price metrics are met (each a "Stock Metric") either on or before the second or on or before the fourth anniversary of the grant date, as applicable. If a Stock Metric is met on or before the first anniversary of the grant date, then 50% of the RSUs vest on the first anniversary of the grant date and the remainder will vest on the second anniversary of the grant date. If a Stock Metric is achieved after the first anniversary of the grant date and on or before the fourth anniversary of the grant date, then 50% of the RSUs vest on the date that the Stock Metric is achieved and the remaining 50% of the RSUs vest on the first anniversary of the initial vesting date. Special vesting provisions apply in the case of a change in control transaction.

SEC source: 0001209191-22-021774 · doc4.xml · derivative · entry 3

Delaney William E IV · CIK 0001812734 · Chief Scientific Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 100,000

Underlying: Common Stock · 100,000 shares

Expires 2032-03-29

F5 · derivative.exercise_date: Grant of stock options. The stock options vest over four years, assuming continuous service on each vesting date, as follows: 25% vest on the first anniversary of the date of grant, March 29, 2023; and the remaining 75% vest in 36 approximately equal monthly installments, with the options becoming fully vested on March 29, 2026.

SEC source: 0001209191-22-021774 · doc4.xml · nonDerivative · entry 1

Delaney William E IV · CIK 0001812734 · Chief Scientific Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 79,121

F1 · shares: Grant of restricted stock units. The restricted stock units vest in four equal installments, assuming continuous service on each vesting date, as follows: March 29, 2023; March 29, 2024; March 29, 2025; and March 29, 2026.

F2 · balance_after: Includes 1,000 shares acquired under the Assembly Biosciences, Inc. 2018 Employee Stock Purchase Plan on November 14, 2021.

SEC source: 0001209191-21-036880 · doc4.xml · nonDerivative · entry 1

Delaney William E IV · CIK 0001812734 · Chief Scientific Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 53,121

F1 · kind: 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.

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $3.98 to $4.08, 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.

F3 · balance_after: Includes 1,000 shares acquired under the Assembly Biosciences, Inc. 2018 Employee Stock Purchase Plan on May 14, 2021.

SEC source: 0001209191-21-024643 · doc4.xml · derivative · entry 2

Delaney William E IV · CIK 0001812734 · Chief Scientific Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 67,500

Underlying: Common Stock · 67,500 shares

Expires 2031-03-29

F2 · derivative.exercise_date: Grant of stock options. The stock options vest over four years, assuming continuous service on each vesting date, as follows: 25% vest on the first anniversary of the date of grant, March 29, 2022; and the remaining 75% vest in 36 approximately equal monthly installments, with the options becoming fully vested on March 29, 2025.

SEC source: 0001209191-21-024643 · doc4.xml · nonDerivative · entry 1

Delaney William E IV · CIK 0001812734 · Chief Scientific Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 56,250

F1 · shares: Grant of restricted stock units. The restricted stock units vest in four approximately equal installments, assuming continuous service on each vesting date, as follows: March 29, 2022; March 29, 2023; March 29, 2024; and March 29, 2025.

SEC source: 0001209191-20-032903 · doc4.xml · derivative · entry 2

Delaney William E IV · CIK 0001812734 · CSO, Virology

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 100,000

Underlying: Common Stock · 100,000 shares

Expires 2030-05-27

F2 · derivative.exercise_date: Grant of stock options. The stock options vest over four years, assuming continuous service on each vesting date, as follows: 25% vest on the first anniversary of the date of grant, May 27, 2021; and the remaining 75% vest in 36 approximately equal monthly installments, with the options becoming fully vested on May 27, 2024.

SEC source: 0001209191-20-032903 · doc4.xml · nonDerivative · entry 1

Delaney William E IV · CIK 0001812734 · CSO, Virology

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 45,000

F1 · shares: Grant of restricted stock units. The restricted stock units vest in four equal installments, assuming continuous service on each vesting date, as follows: May 27, 2021; May 27, 2022; May 27, 2023; and May 27, 2024.