enGene Therapeutics Inc. New Standards Disclosure

Recently Adopted Accounting Pronouncements

In November 2023, the Financial Accounting Standards Board (“FASB”) issued ASU 2023-07, Segment Reporting (Topic 280: Improvements to Reportable Segment Disclosures) (“ASU 2023-07”), which requires public entities to disclose information about their reportable segments’ significant expenses on an interim and annual basis. All disclosure requirements under ASU 2023-07 are also required for public entities with a single reportable segment. The ASU is effective for annual periods beginning after December 15, 2023 and for interim periods within fiscal years beginning after December 15, 2024. The Company adopted this accounting standard during the year ended October 31, 2025 and there was no impact on the Company’s reportable segments identified. Required disclosures have been included in Note 15 "Segment Reporting".

Recently Issued Accounting Pronouncements – Not Yet Adopted

In September 2025, the FASB issued ASU 2025-06, Intangibles - Goodwill and Other - Internal Use Software (Subtopic 350-40) Targeted Improvements to the Accounting for Internal-Use Software, which removes references to project stages and clarified when the Company is required to begin capitalizing eligible costs. The new guidance is effective for fiscal years beginning after December 15, 2027, and interim periods within those fiscal years, with early adoption permitted. ASU 2025-06 may be applied retrospectively or prospectively. The Company is currently evaluating the effect of this updated standard on its consolidated financial statements and related disclosures.

In November 2024, the FASB issued ASU 2024-03, Income Statement - Reporting Comprehensive Income- Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses, as further clarified by ASU 2025-01, Income Statement - Reporting Comprehensive Income- Expense Disaggregation Disclosures (Subtopic 220-40): Clarifying the Effective Date, issued in January, 2025, which requires entities to disclose additional information about specific expense categories in the notes to the financial statements. This ASU is effective for annual periods beginning after December 15, 2026 and for interim periods within fiscal years beginning after December 15, 2027. Early adoption is permitted. ASU 2024-03 may be applied retrospectively or prospectively. The Company is currently evaluating the effect of this updated standard on its consolidated financial statements and related disclosures.

In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740) - Improvements to Income Tax Disclosures, which improves transparency of income tax disclosures by requiring (1) consistent categories and greater disaggregation of information in the rate reconciliation and (2) income taxes paid disaggregated by jurisdiction. ASU No 2023-09 is effective for the Company's annual financial statements for the year ending October 31, 2026. The Company is currently evaluating the impact of the guidance on the financial statements and related disclosures.

In October 2023, the FASB issued ASU 2023-06, Disclosure Improvements: Codification Amendments in Response to the SEC's Disclosure Update and Simplification Initiative, which amends GAAP to reflect updates and simplifications to certain disclosure and presentation requirements referred to FASB by the SEC. The targeted amendments incorporate 14 of the 27 disclosures referred by the SEC into codification. Each amendment in ASU 2023-06 is effective on the date on which the SEC's removal of the related disclosure requirement from Regulation S-X or Regulation S-K becomes effective but will not be effective if the SEC has not removed the applicable disclosure requirements by June 30, 2027. Early adoption is prohibited. The Company is currently evaluating the impact of the amendments on its financial statements and related disclosures.