| Segment reporting |
The Company is advancing a pipeline of innovative gene therapies seeking to deliver to patients suffering from rare and other devastating diseases single treatments with potentially curative results. The Company manages the operations related to these research and development activities within one operating segment because they rely on a common set of infrastructure, resources and technology of the products and production processes, types of customers, distribution methods and regulatory environment. The leadership team is identified as the Chief Operating Decision Maker (“CODM”). The CODM allocates resources to research projects and clinical candidates based on scientific data as well as quantitative and qualitative expected risk-adjusted returns on investment. The CODM uses segment operating loss to monitor that cash operating losses remain within the approved budget. The accounting policies of the operating segment are the same as those described in the summary of significant accounting policies. | | | | | | | | | | | | | | | Three months ended June 30, | | Six months ended June 30, | | | 2026 | | 2025 | | 2026 | | 2025 | | | | (in thousands) | | (in thousands) | Revenue | | $ | 5,841 | | $ | 5,262 | | $ | 9,403 | | $ | 6,829 | Less: | | | | | | | | | | | | | Employee related expenses | | | (16,960) | | | (14,525) | | | (33,746) | | | (28,741) | Laboratory and development expenses | | | (17,387) | | | (15,593) | | | (32,148) | | | (31,560) | Professional fees | | | (1,756) | | | (3,124) | | | (6,263) | | | (5,181) | Information technology system costs(2) | | | (1,427) | | | (838) | | | (3,086) | | | (1,839) | Facility expenses | | | (1,437) | | | (1,704) | | | (2,984) | | | (3,371) | Other segment items(1) (2) | | | (2,511) | | | (1,804) | | | (6,024) | | | (2,773) | Segment operating loss | | | (35,637) | | | (32,326) | | | (74,848) | | | (66,636) | Reconciliation | | | | | | | | | | | | | Depreciation and amortization expense | | | (4,907) | | | (3,630) | | | (7,863) | | | (8,157) | Share-based compensation expense | | | (5,016) | | | (5,084) | | | (10,106) | | | (9,494) | Fair value (loss) / gain - contingent consideration | | | (1,256) | | | (2,254) | | | 82 | | | (3,470) | Fair value loss - Liability related to pre-funded warrants | | | (15,970) | | | — | | | (12,201) | | | — | Foreign currency (losses) / gains, net | | | (1,730) | | | 18,638 | | | (4,024) | | | 25,810 | Interest income | | | 5,051 | | | 3,524 | | | 10,280 | | | 7,651 | Interest expense - Royalty Financing Agreement | | | (12,963) | | | (13,770) | | | (25,584) | | | (27,079) | Interest expense - Hercules loan facility | | | (1,403) | | | (1,821) | | | (2,813) | | | (3,621) | Other reconciling items | | | (5,387) | | | (571) | | | (5,188) | | | 4,561 | Consolidated loss before income tax expense | | $ | (79,218) | | $ | (37,294) | | $ | (132,265) | | $ | (80,435) |
| (1) | Other segment items included in segment operating loss include costs related to intellectual property and insurance offset by income related to payments received from European authorities to subsidize the Company’s research and development in the Netherlands. |
| (2) | The comparative amounts for the three and six months ended June 30, 2025 have been adjusted to reflect the level of detail at which the CODM reviews segment operating expenses in 2026, with information technology system costs presented as a separate line item and consumables included within other segment items for all periods presented. |
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