The following table illustrates information about segment revenue, significant segment expenses and segment operating loss for the periods presented (in thousands):

(1) The significant expense categories and amounts align with the segment-level information that is regularly provided to the CODM.

(2) Research and development expense for the three and six months ended June 30, 2026 excludes $7.8 million and $15.7 million of stock-based compensation expense, respectively, and $2.2 million and $4.4 million of depreciation expense, respectively. Research and development expense for the three and six months ended June 30, 2025 excludes

$7.8 million and $17.5 million of stock-based compensation expense, respectively, and $2.4 million and $4.8 million of depreciation expense, respectively.

(3) Acquired in-process research and development expense for the three and six months ended June 30, 2026 was not material. The $96.3 million acquired in-process research and development expense for the three and six months ended June 30, 2025 is attributable to the costs incurred upon entering the Sirius Agreement, as described in Note 6 of the notes to our unaudited condensed consolidated financial statements included in this Quarterly Report on Form 10-Q.

(4) General and administrative expense for the three and six months ended June 30, 2026 excludes $9.5 million and $17.9 million of stock-based compensation expense, respectively, and $2.1 million and $4.2 million of depreciation expense, respectively. General and administrative expense for the three and six months ended June 30, 2025 excludes $9.8 million and $20.3 million of stock-based compensation expense, respectively, and $2.3 million and $4.6 million of depreciation expense, respectively.

(5) Collaboration costs specific to the Vertex Hemoglobinopathy Agreements (as defined in Note 6) accounted for under ASC 808 are presented within “collaboration expense, net” in the condensed consolidated statements of operations and comprehensive loss.

(6) In the second quarter of 2025, the Company entered into the Sirius Agreement (as defined in Note 6). Collaboration costs, net of reimbursements, related to the Sirius Collaboration Products under the Sirius Agreement are presented within “research and development expense” in the condensed consolidated statements of operations and comprehensive loss. In the first quarter of 2026, the significant expense categories reviewed by the CODM were updated to include collaboration costs, net of reimbursements, associated with the Sirius Collaboration Products. As a result, the Company recast segment amounts for the three and six months ended June 30, 2025 to reflect the updated significant expense categories.

(7) Other segment items include interest income (expense), net, the change in fair value of corporate equity securities and income tax expense.