| Name | Relationship | Address | Signature | Signature date | CIK |
|---|---|---|---|---|---|
| RA CAPITAL MANAGEMENT, L.P. | Director, 10%+ Owner | 200 BERKELEY STREET, 18TH FLOOR, BOSTON | /s/ Peter Kolchinsky, Manager of RA Capital Management, L.P. | 2025-06-05 | 0001346824 |
| RA Capital Healthcare Fund LP | Director, 10%+ Owner | 200 BERKELEY STREET, 18TH FLOOR, BOSTON | /s/ Peter Kolchinsky, Manager of RA Capital Healthcare Fund GP, LLC, the General Partner of RA Capital Healthcare Fund, L.P. | 2025-06-05 | 0001315082 |
| RA Capital Nexus Fund II, L.P. | Director | 200 BERKELEY STREET, 18TH FLOOR, BOSTON | /s/ Peter Kolchinsky, Manager of RA Capital Nexus Fund II GP, LLC, the General Partner of RA Capital Nexus Fund II, L.P. | 2025-06-05 | 0001825376 |
| Kolchinsky Peter | Director, 10%+ Owner | C/O RA CAPITAL MANAGEMENT, L.P., 200 BERKELEY STREET, 18TH FLOOR, BOSTON | /s/ Peter Kolchinsky, individually | 2025-06-05 | 0001384859 |
| Shah Rajeev M. | Director, 10%+ Owner | C/O RA CAPITAL MANAGEMENT, L.P., 200 BERKELEY STREET, 18TH FLOOR, BOSTON | /s/ Rajeev Shah, individually | 2025-06-05 | 0001619841 |
| Type | Sym | Class | Transaction | Value $ | Shares | Change % | * Price $ | Shares After | Date | Ownership | Footnotes |
|---|---|---|---|---|---|---|---|---|---|---|---|
| transaction | ABOS | Common Stock | Award | $0 | +12.8K | $0.00 | 12.8K | Jun 4, 2025 | See footnotes | F1, F2, F3 | |
| holding | ABOS | Common Stock | 13M | Jun 4, 2025 | See footnotes | F2, F4 | |||||
| holding | ABOS | Common Stock | 1.3M | Jun 4, 2025 | See footnotes | F2, F5 | |||||
| holding | ABOS | Common Stock | 589K | Jun 4, 2025 | See footnotes | F2, F6 |
| Type | Sym | Class | Transaction | Value $ | Shares | Change % | * Price $ | Shares After | Date | Underlying Class | Amount | Exercise Price | Ownership | Footnotes |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| transaction | ABOS | Stock Option (Right to Buy) | Award | $0 | +19.5K | $0.00 | 19.5K | Jun 4, 2025 | Common Stock | 19.5K | $1.07 | See Footnotes | F2, F3, F7 |
| Id | Content |
|---|---|
| F1 | Represents the grant of a restricted stock unit ("RSU") award to Laura Stoppel pursuant to the Issuer's non-employee director compensation policy. Each RSU represents a contingent right to receive one share of the Issuer's Common Stock. The RSUs will vest in full on the earlier of June 4, 2026 or the Issuer's 2026 annual stockholder meeting, subject to Dr. Stoppel's continuous service as a director through such vesting date. |
| F2 | RA Capital Management, L.P. (the "Adviser") is the investment manager for RA Capital Healthcare Fund, L.P. (the "Fund"), RA Capital Nexus Fund II, L.P. (the "Nexus Fund II") and a separately managed account (the "Account"). The general partner of the Adviser is RA Capital Management GP, LLC (the "Adviser GP"), of which Dr. Peter Kolchinsky and Mr. Rajeev Shah are the managing members. Each of the Adviser, the Adviser GP, the Fund, the Nexus Fund II, Dr. Kolchinsky, and Mr. Shah disclaim beneficial ownership of any of the reported securities, except to the extent of its or his respective pecuniary interest therein. |
| F3 | Under Dr. Stoppel's arrangement with the Adviser, Dr. Stoppel holds the RSU and the option for the benefit of the Fund and the Nexus Fund II. Dr. Stoppel is obligated to turn over to the Adviser any net cash or stock received upon exercise of the option or settlement of the RSU, as applicable, which will offset advisory fees owed by the Fund and the Nexus Fund II to the Adviser. The Reporting Persons therefore disclaim beneficial ownership of the RSU, the option and underlying common stock. |
| F4 | Held directly by the Fund. |
| F5 | Held directly by the Nexus Fund II. |
| F6 | Held directly by the Account. |
| F7 | Represents the grant of an option to Dr. Stoppel pursuant to the Issuer's non-employee director compensation policy. The shares subject to the option will vest on the earlier of June 4, 2026 or the 2026 annual stockholder meeting, subject to Dr. Stoppel's continuous service as a director through such vesting date. |
Laura Stoppel, a Principal of the Adviser, serves on the Issuer's board of directors.