| Name | Relationship | Address | Signature | Signature date | CIK |
|---|---|---|---|---|---|
| Casdin Capital, LLC | Director | 1350 AVENUE OF THE AMERICAS, SUITE 2600, NEW YORK | Casdin Capital LLC, By: /s/ Eli Casdin, Managing Member | 2025-05-15 | 0001534261 |
| Casdin Eli | Director | 1350 AVENUE OF THE AMERICAS, SUITE 2600, NEW YORK | /s/ Eli Casdin, Eli Casdin | 2025-05-15 | 0001534264 |
| Casdin Partners Master Fund, L.P. | Director | 1350 AVENUE OF THE AMERICAS, SUITE 2600, NEW YORK | Casdin Partners Master Fund, LP, By: Casdin Partners GP, LLC, its General Partner, By: /s/ Eli Casdin, Managing Member | 2025-05-15 | 0001534265 |
| Casdin Partners GP, LLC | Director | 1350 AVENUE OF THE AMERICAS, SUITE 2600, NEW YORK | Casdin Partners GP LLC, By: /s/ Eli Casdin, Managing Member | 2025-05-15 | 0001534260 |
| Type | Sym | Class | Transaction | Value $ | Shares | Change % | * Price $ | Shares After | Date | Ownership | Footnotes |
|---|---|---|---|---|---|---|---|---|---|---|---|
| transaction | TSVT | Common Stock, par value $0.0001 per share | Disposition pursuant to a tender of shares in a change of control transaction | -$113K | -22.6K | -100% | $5.00 | 0 | May 13, 2025 | Direct | F1, F2, F3 |
| transaction | TSVT | Common Stock, par value $0.0001 per share | Disposition pursuant to a tender of shares in a change of control transaction | -$10M | -2M | -100% | $5.00 | 0 | May 13, 2025 | See footnote | F1, F2, F4 |
| Type | Sym | Class | Transaction | Value $ | Shares | Change % | * Price $ | Shares After | Date | Underlying Class | Amount | Exercise Price | Ownership | Footnotes |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| transaction | TSVT | Stock Options (Right to buy) | Disposed to Issuer | -12.1K | -100% | 0 | May 13, 2025 | Common Stock, par value $0.0001 per share | 12.1K | $3.93 | Direct | F3, F5 | ||
| transaction | TSVT | Stock Options (Right to buy) | Disposed to Issuer | -33.4K | -100% | 0 | May 13, 2025 | Common Stock, par value $0.0001 per share | 33.4K | $4.54 | Direct | F3, F5 |
Casdin Capital, LLC is no longer subject to Section 16 filing requirements. Form 4 or Form 5 obligations may continue.
| Id | Content |
|---|---|
| F1 | Represents securities that were tendered in connection with the Agreement and Plan of Merger (the "Merger Agreement"), dated March 10, 2025, by and among 2seventy bio, Inc. (the "Company"), Daybreak Merger Sub Inc. ("Merger Sub") and Bristol-Myers Squibb Company ("Parent"). Following completion of a cash tender offer by Merger Sub to acquire all of the issued and outstanding shares of the Company's common stock, par value $0.0001 per share (the "Company Common Stock") for $5.00 per share (the "Merger Consideration"), Merger Sub merged with and into the Company, with the Company continuing as the surviving corporation and a whole owned subsidiary of Parent (the "Merger"). |
| F2 | cont'd from footnote (1): Each restricted stock unit in respect of Company Common Stock ("Company RSU Award"), whether vested or unvested, that was outstanding immediately prior to the effective time of the Merger (the "Effective Time") was fully vested, was cancelled and automatically converted into the right to receive, for each share of Company Common Stock underlying such Company RSU Award immediately prior to the Effective Time, an amount (without interest and subject to deduction for any required withholding under applicable law relating to tax) in cash equal to the Merger Consideration. Additionally, effective as of the Effective Time and as a result of the Merger, Eli Casdin ceased to be a member of the Company's board of directors. |
| F3 | The securities were owned directly by Eli Casdin. |
| F4 | The securities were owned directly by Casdin Partners Master Fund, L.P. (the "Master Fund") and may be deemed to have been indirectly beneficially owned by (i) Casdin Capital, LLC, the investment adviser to the Master Fund ("Casdin"), (ii) Casdin Partners GP, LLC, the general partner of the Master Fund (the "GP"), and (iii) Eli Casdin, the managing member of Casdin and the GP. |
| F5 | Each option to purchase Company Common Stock ("Company Option"), whether vested or unvested, that was outstanding and unexercised immediately prior to the Effective Time and had a per share exercise price that was less than the Merger Consideration was fully vested, was cancelled and automatically converted into the right to receive, for each share of Company Common Stock underlying such Company Option immediately prior to the Effective Time, an amount (without interest and subject to deduction for any required withholding under applicable law relating to tax) in cash equal to the excess of the Merger Consideration over the per share exercise price of such Company Option. |
Each Reporting Person disclaims beneficial ownership in the securities reported on this Form 4 except to the extent of its pecuniary interest, if any, therein, and this report shall not be deemed to be an admission that such Reporting Person is the beneficial owner of such securities for purposes of Section 16 or for any other purpose.