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12-month complete response data from LEGEND pivotal cohort and subsequent FDA engagement planned for 2H 2026 Initiation of Biologics License Application (BLA) filing for detalimogene planned for 2H 2026 First patients enrolled in surfactant plus detalimogene cohort Approximately 50% reduction in force to streamline operations and preserve cash to focus on BLA and precommercial activities Well capitalized with cash, cash equivalents and marketable securities of $285 million BOSTON & MONTREAL, June 15, 2026--(BUSINESS WIRE)--enGene Therapeutics Inc. (Nasdaq: ENGN, "enGene" or the "Company"), a clinical-stage, non-viral genetic medicines company today announced its financial results for the second quarter ended April 30, 2026, and provided clinical and corporate updates. "Feedback from the urology community on the emerging detalimogene without surfactant profile, presented at the AUA meeting in May, supports our plan to await mature durability data in the second half of 2026 and meet with the FDA about initiating a BLA submission for detalimogene before year end," said Ron Cooper, President and Chief Executive Officer, enGene. Mr. Cooper continued, "We are also encouraged by the interest in the detalimogene surfactant bladder rinse study from the medical community. With patients already enrolled, we are optimistic about the potential to further enhance efficacy while maintaining the ease of use and tolerability profile that has resonated with urologists." "To preserve shareholder capital as we await additional durability data and meetings with the FDA, we made the very difficult decision to downsize the organization to streamline operations. We are sincerely grateful to the enGeneers who have created a high-performance culture and helped advance detalimogene and our mission to provide people living with NMIBC a new treatment option," added Mr. Cooper. Recent Clinical Updates LEGEND Pivotal Cohort 1: During a plenary presentation at the recent American Urological Association (AUA) meeting, interim data were shared from LEGEND’s pivotal Cohort 1 studying detalimogene without surfactant in high-risk (HR), Bacillus Calmette-Guérin (BCG)-unresponsive non-muscle invasive bladder cancer (NMIBC) with carcinoma in-situ (CIS). Efficacy overview: 54% (95% CI: 45%, 63%) complete response (CR) at any time (67/124) Low rate of progression to muscle invasive or more advanced disease (3.2%) Safety overview: Low percentage of patients experienced treatment-related adverse events (TRAEs) leading to treatment interruption (2.4%) and treatment discontinuation (2.4%) Twenty-one patients were pending disease assessments at either six-, nine-, or 12-months as of the data cutoff date of April 21, 2026. enGene is awaiting 12-month CR data from Cohort 1, as well as the majority of 12-month durability data, and expects to engage with the FDA in 2H 2026 to discuss a BLA filing. Detalimogene plus Surfactant Cohort: In tandem with its pivotal update in May, the Company announced the initiation of an additional LEGEND cohort, which incorporates a short surfactant bladder rinse using diluted polidocanol solution. Polidocanol is an FDA-approved product used for the treatment of spider and reticular veins. Surfactants have been shown to boost efficacy with other gene therapies in preclinical models and were subsequently incorporated into clinical development of those gene therapies. In murine models tested by the Company, pretreatment with polidocanol demonstrated a 10-fold increase in mean IL-12 expression and was able to boost efficacy of a subtherapeutic dose of detalimogene. Findings were validated in a large mammal model tested by the Company where a surfactant rinse increased the distribution of detalimogene nanoparticles throughout the bladder by approximately 50% and IL-12 expression by nine-fold. The first patients have been enrolled in the surfactant cohort, and the Company may enroll up to 80 patients in this global cohort. The Company believes this approach has the potential to further enhance efficacy and durability while preserving the simplicity, tolerability, and office-based administration profile that may make detalimogene a preferred option for community urology practices, where approximately 80% of NMIBC patients receive treatment. LEGEND Cohorts 2a, 2b and 3: As part of cash conservation efforts, the Company has stopped enrollment in these additional cohorts and plans to reevaluate its strategy for them following discussion with the FDA in 2H 2026. Recent Corporate Updates Reduction in Force and Executive Departures: In June 2026, enGene implemented a plan to reduce its workforce by approximately 50% to streamline operations and preserve cash. The Company has retained personnel and resources required to meet its key strategic goals and milestones, including completion of LEGEND Cohort 1; enrolling the detalimogene plus surfactant cohort; meeting with the FDA and planning for BLA initiation in 2H 2026; and completing necessary pre-commercial activities required to support the planned commercial launch of detalimogene in 2027. In conjunction with its reduction in force, the following executive officers will depart from the Company, effective July 15, 2026: Ryan Daws, Chief Financial Officer, Lee Giguere, Chief Legal Officer and Alex Nichols, Chief Strategy and Operations Officer. Anthony Cheung, Chief Scientific Officer, will continue in his role through September 30, 2026, after which, he will transition into a consulting arrangement. Hussein Sweiti, M.D., Chief Medical Officer, stepped down from his position to pursue a new professional opportunity, effective June 14, 2026. Effective immediately, William Grossman, M.D., Ph.D., a member of enGene’s Board of Directors, will act as interim Chief Medical Officer. He is the former Senior Vice President and Therapeutic Area Head of Oncology Clinical Development at Gilead Sciences Inc. where he oversaw the oncology portfolio (early and late-stage clinical development) and collaboration programs. Prior to that, he held several Chief Medical Officer roles including at Arcus Biosciences and Bellicum Pharmaceuticals. He has held additional leadership roles at Genentech/Roche, Merck, AbbVie, and Biothera. Dr. Grossman received his M.D. and Ph.D. in Immunology from Washington University School of Medicine’s Medical Scientist Training Program and completed his medical and post-doctoral training in both the Divisions of Pediatrics and Medicine at Washington University School of Medicine. He also currently serves on several advisory boards and will continue to serve on enGene’s Board of Directors as a non-independent Director during his interim CMO role. Constantine Chinoporos, who joined the Company in May as a business development consultant, is expected to act as enGene’s interim Chief Business Officer. Mr. Chinoporos brings deep experience across business development, licensing, and M&A in the biopharma sector. He is a member of the Board of Directors at Geron Corporation, and most recently served as Chief Operating Officer and Chief Business Officer of Applied Therapeutics. Prior to his role at Applied Therapeutics, Mr. Chinoporos served as Chief Business Officer at Albireo Pharmaceuticals, Inc. from 2021 until its acquisition by Ipsen S.A. in 2023. From 2015 to 2021, he served as Chief Business Officer at Boston Pharmaceuticals, Inc. Previously, he held senior positions in worldwide licensing, business development, corporate development, corporate finance and alliance management at Sanofi S.A., Genzyme Corporation, and Eli Lilly and Company. Mr. Chinoporos holds an M.B.A. from the Johnson Graduate School of Management at Cornell University and a B.A. in History from Cornell University. Anticipated Milestones 12-month complete response data for all of Cohort 1 and pre-BLA meeting in 2H 2026 Initiation of BLA filing for detalimogene in 2H 2026 Potential detalimogene FDA approval decision and platform designation in 2027 Second Quarter 2026 Financial Results As of April 30, 2026, cash, cash equivalents and marketable securities were $285.2 million providing significant operational flexibility. Total operating expenses were $32.0 million for the three months ended April 30, 2026, compared to $27.1 million for the three months ended April 30, 2025. Research and development expenses increased by $2.0 million, primarily driven by increased personnel and clinical costs related to our LEGEND trial, completion of PPQ batch manufacturing and preparation to initiate the submission of a planned Biologics License Application with the FDA in the second half of 2026. General and administrative expenses increased by $2.9 million, primarily driven by annualization of personnel-related costs and increased facility costs. For the three months ended April 30, 2026, net loss attributable to common shareholders was approximately $30.2 million, or $0.43 per share, compared to approximately $25.8 million, or $0.51 per share, for the three months ended April 30, 2025. The increase in net loss is mainly attributed to the increase in operating expenses, partially offset by net interest income earned during the period. About Non-Muscle Invasive Bladder Cancer (NMIBC) Non-muscle invasive bladder cancer (NMIBC) is a disease that poses a significant burden on both patients and clinics and has a massive economic impact on the healthcare system. NMIBC occurs when cancer cells grow in the tissues that line the interior of the bladder, but the cancer has not yet penetrated the muscle of the bladder wall. NMIBC can present as papillary outgrowths from the bladder wall, which are typically resected, or as carcinoma in situ (CIS), which consists of flat, multifocal lesions that cannot be resected. The two forms can also co-occur. About 75%-80% of new bladder cancer diagnoses are NMIBC. Patients suffering from high-risk NMIBC who are unresponsive to the standard of care, Bacillus Calmette-Guérin (BCG), face high rates of disease recurrence (50%-70%) and are potentially subject to full removal of the bladder (cystectomy) as a curative but life-altering next step. About Detalimogene Voraplasmid Detalimogene is a novel, investigational, non-viral gene therapy for patients with high-risk, non-muscle invasive bladder cancer (NMIBC), including Bacillus Calmette-Guérin (BCG)-unresponsive disease. It is designed to be instilled in the bladder and elicit a powerful yet localized anti-tumor immune response. Detalimogene was developed using the Company’s Dually Derivatized Oligochitosan® (DDX) platform, a technology designed to transform how gene therapies are accessed by patients and utilized by clinicians. Medicines developed with the DDX platform can potentially overcome the limitations of viral-based gene therapies, reduce complexities related to safe handling and cold storage, and streamline both manufacturing processes and administration paradigms. Regenerative Medicine Advanced Therapy (RMAT) and Fast Track Designations Detalimogene has received Regenerative Medicine Advanced Therapy (RMAT) and Fast Track designations from the U.S. Food and Drug Administration (FDA) based on its potential to address the high unmet medical need for patients with BCG-unresponsive carcinoma in situ (CIS) NMIBC with or without resected papillary tumors who are unable to undergo cystectomy. These designations are intended to expedite the development and review of drugs intended to treat serious or life-threatening conditions and fill an unmet medical need. Detalimogene has also been selected for the FDA’s Chemistry, Manufacturing, and Controls (CMC) Development and Readiness Pilot (CDRP) program, designed to facilitate CMC development for therapies with compressed clinical development timeframes based on the anticipated clinical benefits of earlier patient access to the therapy. About the LEGEND Trial Detalimogene is being evaluated in the ongoing, open-label, multi-cohort, Phase 2 LEGEND trial to establish its safety and efficacy in high-risk NMIBC. LEGEND’s pivotal cohort (Cohort 1) consists of 125 patients with high-risk, BCG-unresponsive NMIBC with CIS (with or without papillary disease) and is designed to serve as the basis of the Company’s planned Biologics License Application (BLA) filing. In addition to this pivotal cohort, LEGEND includes four additional cohorts, including NMIBC patients with CIS who are naïve to treatment with BCG (Cohort 2a); NMIBC patients with CIS who have been exposed to BCG but have not received adequate BCG treatment (Cohort 2b); BCG-unresponsive high-risk NMIBC patients with papillary-only disease (Cohort 3); and BCG-unresponsive high-risk NMIBC patients with CIS who receive polidocanol plus detalimogene. About enGene enGene Therapeutics Inc. is a clinical-stage biotechnology company mainstreaming non-viral genetic medicine through the delivery of therapeutics to mucosal tissues and other organs, with the goal of creating new ways to address diseases with high clinical needs. enGene’s lead program is detalimogene voraplasmid (also known as detalimogene) for patients with non-muscle invasive bladder cancer (NMIBC), a disease with a high clinical burden. Detalimogene is being evaluated in the ongoing multi-cohort LEGEND Phase 2 trial, which includes a pivotal cohort studying detalimogene in high-risk, Bacillus Calmette-Guérin (BCG)-unresponsive patients with carcinoma in situ (CIS) with or without concomitant papillary disease. Detalimogene was developed using enGene’s proprietary Dually Derivatized Oligochitosan (DDX) platform, which enables penetration of mucosal tissues and delivery of a wide range of sizes and types of cargo, including DNA and various forms of RNA. To learn more, please visit enGene.com and follow us on LinkedIn, X and BlueSky. Forward-Looking Statements Certain statements contained in this press release may constitute "forward-looking statements" within the meaning of the safe harbor provisions of the Private Securities Litigation Reform Act of 1995, and "forward-looking information" within the meaning of Canadian securities laws (collectively, "forward-looking statements"). enGene’s forward-looking statements include, but are not limited to, statements relating to the Company’s future plans, expectations, hopes, beliefs, intentions, goals or strategies regarding the future. In addition, any statements that refer to projections, forecasts or other characterizations of future events or circumstances, including any underlying assumptions, are forward-looking statements. The words "anticipate", "appear", "approximate", "believe", "continue", "could", "estimate", "expect", "foresee", "goal", "intends", "may", "might", "plan", "possible", "potential", "predict", "project", "seek", "should", "would", and similar expressions (or the negative version of such words or expressions) may identify forward-looking statements, but the absence of these words does not mean that a statement is not forward-looking. Forward-looking statements may include, for example, statements about: detalimogene’s potential efficacy, durability, safety, tolerability and ease of use profile, the development of detalimogene, enGene’s estimates regarding expenses, debt obligations and capital requirements necessary to fund its current operating plan, the expected period over which enGene estimates its cash and marketable securities will be sufficient to fund its current operating plan, the intended objectives and benefits of the reduction in force, including any estimated cost savings, the potential benefits of detalimogene, plans regarding regulatory interactions and a potential BLA submission for detalimogene, plans regarding updates on the LEGEND study, including clinical data and engagement with the FDA, the potential benefits of combining a surfactant bladder rinse with detalimogene, plans for the additional cohorts of the LEGEND study, and the potential benefits of medicines developed with the DDX platform. Such statements are subject to numerous important factors, risks and uncertainties, many of which are beyond enGene’s control, that may cause actual events or results to differ materially from enGene’s current expectations. For example, there can be no guarantee that detalimogene will successfully complete necessary clinical development phases, including achieving positive results in the pivotal cohort of the LEGEND study, or that those results or any feedback from regulatory authorities will ultimately lead to a BLA submission for, and the approval of, detalimogene. Management’s expectations and, therefore, any forward-looking statements in this press release could also be affected by risks, uncertainties and assumptions relating to a number of other factors, which could cause the Company’s actual results, performance or achievements to differ materially from those expressed or implied by the forward-looking statements, including, without limitation, the inability of preliminary clinical data to predict the final results of the trial, changes in the results from enGene’s clinical trials, including due to new data collected from the ongoing LEGEND study or future studies, subsequent analysis of existing data, and audit and verification procedures; the content and timing of decisions made by the FDA and other regulatory authorities; the Company’s ability to recruit and retain qualified scientific and management personnel, establish clinical trial sites and enroll patients in its clinical trials, execute on the Company’s clinical development plans; and its ability to secure regulatory approval on anticipated timelines, and other risks and uncertainties detailed in filings with Canadian securities regulators on SEDAR+ and with the U.S. Securities and Exchange Commission ("SEC") on EDGAR, including those described in the "Risk Factors" section of the Company’s Annual Report on Form 10-K for the fiscal year ended October 31, 2025 (copies of which may be obtained at www.sedarplus.ca or www.sec.gov). You should not place undue reliance on any forward-looking statements, which speak only as of the date on which they are made. enGene anticipates that subsequent events and developments will cause enGene’s assessments to change. While enGene may elect to update these forward-looking statements at some point in the future, enGene specifically disclaims any obligation to do so, unless required by applicable law. Nothing in this press release should be regarded as a representation by any person that the forward-looking statements set forth herein will be achieved or that any of the contemplated results of such forward-looking statements will be achieved. View source version on businesswire.com: https://www.businesswire.com/news/home/20260615436479/en/ Contacts Media: [email protected] Investor: [email protected]

54% complete response (CR) rate at any time; 43% six‑month CR rate Low rate of progression to muscle-invasive or higher disease (3.2%) Low percentage of patients experienced treatment-related adverse events (TRAEs) (55%), nearly all of which were mild Low percentage of patients experienced TRAEs leading to treatment interruption (2.4%) or discontinuation (2.4%) Kaplan-Meier estimate of 12-month CR rate is 25% enGene to host webcast to discuss results today, May 7, 2026, at 8:00 a.m. ET BOSTON & MONTREAL, May 07, 2026--(BUSINESS WIRE)--enGene Therapeutics Inc. (Nasdaq: ENGN or "enGene" or the "Company"), a clinical-stage, non-viral genetic medicines company, today reported additional interim results from the pivotal cohort of its ongoing, Phase 2 LEGEND trial of detalimogene voraplasmid (also known as detalimogene) in high-risk, Bacillus Calmette-Guérin (BCG)-unresponsive non-muscle invasive bladder cancer (NMIBC) patients with carcinoma in situ (CIS) with or without concomitant papillary disease, which enrolled 125 patients. These data, as of April 21, 2026, demonstrated that patients treated with detalimogene achieved a 54% complete response (CR) at any time and a 43% CR rate at six months. The progression rate to muscle-invasive or advanced disease was low, at 3.2%. Detalimogene was generally well tolerated with 55% of patients having experienced a treatment-related adverse event, mostly mild (Grade 1 and 2). "These updated data continue to reinforce the favorable safety and tolerability profile of detalimogene and its clinical activity in a heavily pretreated, high-risk NMIBC patient population with limited therapeutic options. Importantly, the low rate of progression to muscle-invasive disease leaves patients eligible for other bladder-sparing therapies," said Ron Cooper, President and Chief Executive Officer, enGene. "While durability outcomes to date are not what we hoped, these data are preliminary. We are focused on evaluating the totality of the data as it evolves and plan to continue to engage with the FDA and the medical community." LEGEND Pivotal Cohort Data Update The interim analysis is based on the 125 patients enrolled in Cohort 1. Patients who discontinued without any disease evaluation or who discontinued after a CR were considered not evaluable for subsequent landmark CR analysis. Efficacy overview: 54% (95% CI: 45%, 63%) CR at any time (67/124) 91% of responses occurred at first disease assessment 43% (95% CI: 34%, 52%) CR rate at 6 months (52/121) with 14% (6/43) of patients having successfully converted from non-CR to CR post re-induction Two re-induced patients have not yet had a 6-month assessment Of the 52 responders at 6 months: 37/44 patients who had a 9-month assessment were in CR; an additional 8 patients are pending evaluation 13/22 patients who had a 12-month assessment were in CR; an additional 11 patients are pending evaluation A maximum of 21 patients, including the 2 currently undergoing re-induction, still have the potential to achieve a CR at 12 months The Kaplan-Meier (KM) estimate of the 12-month duration of response (DoR) is 25% (95% CI: 11%, 41%) The KM estimate for median DoR is 37.3 weeks (range: 31.6-43.9 weeks) Low rate of progression to muscle invasive or more advanced disease (3.2%) Safety overview: 55% of patients experienced a treatment-related adverse event (TRAE) Among patients with any TRAE, 91% experienced Grade 1-2 TRAEs Grade ≥3 TRAEs were reported in 6 patients (4.8%) Low percentage of patients experienced TRAEs leading to treatment interruption (2.4%) and treatment discontinuation (2.4%) Among the 32 patients who had their first disease assessment after the last data analysis (October 24, 2025, reported November 11, 2025), CR rates were lower than previously reported results. The CR rate at any time was 39% and at 6 months was 32% for these patients. A preliminary subgroup analysis has not revealed any material differences in demographics or key disease characteristics. A more comprehensive analysis of these patients, including potential contributing factors, is ongoing. As a beneficiary of FDA’s RMAT designation and a participant in the FDA’s CDRP program, enGene has completed the required FDA manufacturing validation batches and submitted a Statistical Analysis Plan (SAP) to the agency. The Company plans further engagement with the FDA as it approaches a potential Biologics License Application (BLA) filing and plans to provide an update in the second half of 2026. The Company plans to share these data with the broader medical community at a Plenary Presentation at the upcoming American Urological Association meeting on May 15, 2026. Safety Information The overall tolerability profile associated with detalimogene is favorable. Of the 125 patients assessed for safety in Cohort 1, 69 patients (55%) experienced at least one TRAE, which were mainly Grade 1/2 in severity. The most common TRAEs were fatigue (22%), dysuria (14%), micturition urgency (12%), pollakiuria (12%), and bladder spasm (11%). Six patients experienced Grade ≥3 TRAEs, including one Grade 4 TRAE, which has resolved. There were no Grade 5 TRAEs reported. TRAEs leading to dose discontinuations (2.4%) and dose interruptions (2.4%) were rare. Conference Call enGene will host a conference call and live webcast at 8:00 a.m. ET today, May 7, 2026. Individuals interested in listening to the conference call may do so by clicking the following link, which is also available at the "Investors" section of the Company’s website at www.engene.com/investors. Following the live webcast, an archived version of the call will also be available on the Company’s website for 90 days. About Non-Muscle Invasive Bladder Cancer (NMIBC) Non-muscle invasive bladder cancer (NMIBC) is a disease that poses a significant burden on both patients and clinics and has a massive economic impact on the healthcare system. NMIBC occurs when cancer cells grow in the tissues that line the interior of the bladder, but the cancer has not yet penetrated the muscle of the bladder wall. NMIBC can present as papillary outgrowths from the bladder wall, which are typically resected, or as carcinoma in situ (CIS), which consists of flat, multifocal lesions that cannot be resected. The two forms can also co-occur. About 75%-80% of new bladder cancer diagnoses are NMIBC. Patients suffering from high-risk NMIBC who are unresponsive to the standard of care, Bacillus Calmette-Guérin (BCG), face high rates of disease recurrence (50%-70%) and are potentially subject to full removal of the bladder (cystectomy) as a curative but life-altering next step. About Detalimogene Voraplasmid Detalimogene is a novel, investigational, non-viral gene therapy for patients with high-risk, non-muscle invasive bladder cancer (NMIBC), including Bacillus Calmette-Guérin (BCG)-unresponsive disease. It is designed to be instilled in the bladder and elicit a powerful yet localized anti-tumor immune response. Detalimogene was developed using the Company’s Dually Derivatized Oligochitosan® (DDX) platform, a technology designed to transform how gene therapies are accessed by patients and utilized by clinicians. Medicines developed with the DDX platform can potentially overcome the limitations of viral-based gene therapies, reduce complexities related to safe handling and cold storage, and streamline both manufacturing processes and administration paradigms. Detalimogene has received Regenerative Medicine Advanced Therapy (RMAT) and Fast Track designations from the U.S. Food and Drug Administration (FDA) based on its potential to address the high unmet medical need for patients with BCG-unresponsive carcinoma in situ (CIS) NMIBC with or without resected papillary tumors who are unable to undergo cystectomy. These designations are intended to expedite the development and review of drugs to serious or life-threatening conditions and fill an unmet medical need. Detalimogene has also been selected for the FDA’s Chemistry, Manufacturing, and Controls (CMC) Development and Readiness Pilot (CDRP) program, designed to facilitate CMC development for therapies with compressed clinical development timeframes based on the anticipated clinical benefits of earlier patient access to the therapy. About the LEGEND Trial Detalimogene is being evaluated in the ongoing, open-label, multi-cohort, Phase 2 LEGEND trial to establish its safety and efficacy in high-risk NMIBC. LEGEND’s pivotal cohort (Cohort 1) consists of 125 patients with high-risk, BCG-unresponsive NMIBC with CIS (with or without papillary disease) and is designed to serve as the basis of the Company’s planned Biologics License Application (BLA) filing. In addition to this pivotal cohort, LEGEND includes three additional cohorts, including NMIBC patients with CIS who are naïve to treatment with BCG (Cohort 2a); NMIBC patients with CIS who have been exposed to BCG but have not received adequate BCG treatment (Cohort 2b); and BCG-unresponsive high-risk NMIBC patients with papillary-only disease (Cohort 3). About enGene enGene is a clinical-stage biotechnology company mainstreaming non-viral genetic medicine through the delivery of therapeutics to mucosal tissues and other organs, with the goal of creating new ways to address diseases with high clinical needs. enGene’s lead program is detalimogene voraplasmid (also known as detalimogene) for patients with non-muscle invasive bladder cancer (NMIBC), a disease with a high clinical burden. Detalimogene is being evaluated in the ongoing multi-cohort LEGEND Phase 2 trial, which includes a pivotal cohort studying detalimogene in high-risk, Bacillus Calmette-Guérin (BCG)-unresponsive patients with carcinoma in situ (CIS) with or without concomitant papillary disease. Detalimogene was developed using enGene’s proprietary Dually Derivatized Oligochitosan (DDX) platform, which enables penetration of mucosal tissues and delivery of a wide range of sizes and types of cargo, including DNA and various forms of RNA. To learn more, please visit enGene.com and follow us on LinkedIn, X and BlueSky. Forward-Looking Statements Certain statements contained in this press release may constitute "forward-looking statements" within the meaning of the safe harbor provisions of the Private Securities Litigation Reform Act of 1995, and "forward-looking information" within the meaning of Canadian securities laws (collectively, "forward-looking statements"). enGene’s forward-looking statements include, but are not limited to, statements relating to the Company’s future plans, expectations, intentions, strategies and objectives. In addition, any statements that refer to projections, forecasts or other characterizations of future events or circumstances, including any underlying assumptions, are forward-looking statements. The words "anticipate", "appear", "approximate", "believe", "continue", "could", "estimate", "expect", "foresee", "goal", "intend", "may", "might", "plan", "possible", "potential", "predict", "project", "seek", "should", "would", and similar expressions (or the negative version of such words or expressions) may identify forward-looking statements, but the absence of these words does not mean that a statement is not forward-looking. Forward-looking statements may include, for example, statements about: detalimogene’s potential efficacy, durability, safety, tolerability and ease of use profile, the development of detalimogene, the potential benefits of detalimogene, plans regarding regulatory interactions and a potential BLA submission for detalimogene, plans regarding updates on the LEGEND study, including clinical data and engagement with the FDA, and the potential benefits of medicines developed with the DDX platform. Such statements are subject to numerous important factors, risks and uncertainties, many of which are beyond enGene’s control, that may cause actual events or results to differ materially from enGene’s current expectations. For example, there can be no guarantee that detalimogene will successfully complete necessary clinical development phases, including achieving positive results in the pivotal cohort of the LEGEND study, or that those results or any feedback from regulatory authorities will ultimately lead to BLA submission for, and the approval of, detalimogene. Management’s expectations and, therefore, any forward-looking statements in this press release could also be affected by risks, uncertainties and assumptions relating to a number of other factors, which could cause the Company’s actual results, performance or achievements to differ materially from those expressed or implied by the forward-looking statements, including, without limitation, the inability of preliminary clinical data to predict the final results of the trial, changes in the results from enGene’s clinical trials, including due to new data collected from the ongoing LEGEND study or future studies, subsequent analysis of existing data, and audit and verification procedures; the content and timing of decisions made by the FDA and other regulatory authorities; the Company’s ability to recruit and retain qualified scientific and management personnel, establish clinical trial sites and enroll patients in its clinical trials, execute on the Company’s clinical development plans; and its ability to secure regulatory approval on anticipated timelines, and other risks and uncertainties detailed in filings with Canadian securities regulators on SEDAR+ and with the U.S. Securities and Exchange Commission ("SEC") on EDGAR, including those described in the "Risk Factors" section of the Company’s Annual Report on Form 10-K for the fiscal year ended October 31, 2025 (copies of which may be obtained at www.sedarplus.ca or www.sec.gov). You should not place undue reliance on any forward-looking statements, which speak only as of the date on which they are made. enGene anticipates that subsequent events and developments will cause enGene’s assessments to change. While enGene may elect to update these forward-looking statements at some point in the future, enGene specifically disclaims any obligation to do so, unless required by applicable law. Nothing in this press release should be regarded as a representation by any person that the forward-looking statements set forth herein will be achieved or that any of the contemplated results of such forward-looking statements will be achieved. View source version on businesswire.com: https://www.businesswire.com/news/home/20260507845702/en/ Contacts Media contact: JC Molina [email protected] Investor contact: Lauren Stival Hopfer [email protected]

LEGEND pivotal cohort update planned for a spring 2026 medical conference 12-month complete response data from LEGEND pivotal cohort expected in 2H 2026 Biologics License Application (BLA) submission for detalimogene planned for 2H 2026 Cash and marketable securities of $312.5 million expected to provide cash runway into 2H 2028 Expanded $125 million debt facility with Hercules Capital provides additional financial flexibility to advance detalimogene development and commercialization for bladder cancer BOSTON & MONTREAL, March 09, 2026--(BUSINESS WIRE)--enGene Holdings Inc. (Nasdaq: ENGN, "enGene" or the "Company"), a clinical-stage, non-viral genetic medicines company, today announced its financial results for the first quarter ended January 31, 2026, and provided a business update. "As data from LEGEND's pivotal cohort in high-risk, BCG-unresponsive NMIBC continues to mature, we look forward to providing an update at a spring medical conference," said Ron Cooper, President and Chief Executive Officer, enGene. "On the heels of our successful November follow-on offering, we entered 2026 in a position of financial strength and ready to execute. With RMAT and CDRP designations for detalimogene, we are in active dialogue with the FDA to ensure regulatory and manufacturing readiness as we plan for a BLA submission in the second half of this year and potential launch in 2027." Recent Corporate Updates Expanded debt facility: In January 2026, the Company expanded its existing loan and security agreement with Hercules Capital, Inc. (NYSE: HTGC) ("Hercules"), for up to $125 million. Access to the additional non-dilutive capital strengthens enGene’s balance sheet in preparation for its planned Biologics License Application ("BLA") to the U.S. Food and Drug Administration ("FDA") for detalimogene voraplasmid as a treatment for high-risk, Bacillus Calmette-Guérin ("BCG")-unresponsive non-muscle invasive bladder cancer ("NMIBC") with carcinoma in situ ("CIS") in the second half of 2026, and the potential commercial launch of detalimogene should it receive FDA approval. Successful completion of public offering: In November 2025, the Company successfully closed an underwritten public offering of its common shares and pre-funded warrants at an offering price of $8.50 per share and $8.4999 per pre-funded warrant. The offering totaled $140.1 million in net proceeds, following the full exercise of the underwriters’ option to purchase additional shares. LEGEND pivotal cohort update: In November 2025, enGene reported preliminary data from LEGEND’s pivotal cohort for patients enrolled following a protocol amendment implemented in the fourth quarter of 2024. The preliminary analysis of the post-amendment patients with at least one post-baseline disease assessment included 62 patients at 3 months and 37 patients at 6 months and demonstrated: 63% complete response (CR) rate at any time (n=62); 56% CR rate at 3 months (n=62); 62% CR rate at 6 months (n=37), including 4 patients who successfully converted to CR post reinduction; and All 5 patients who completed the 9-month assessment had a CR. The Company completed enrollment of 125 patients in total. Data from these patients demonstrated a generally favorable tolerability profile: 42% of patients experienced a treatment-related adverse event (TRAE); 1.6% of patients experienced dose interruptions due to TRAEs; and 0.8% of patients experienced dose discontinuations due to TRAEs. enGene continues to believe that detalimogene’s emerging profile supports its potential first-line use in patients with high-risk, BCG-unresponsive non-muscle invasive bladder cancer with CIS. CMC Development and Readiness Pilot (CDRP) Program: In November 2025, the Company was selected as one of nine companies to participate in the FDA’s Chemistry, Manufacturing, and Controls (CMC) Development and Readiness Pilot (CDRP) program. The FDA created the CDRP Program to facilitate CMC development for therapies with compressed clinical development timeframes based on the anticipated clinical benefits of earlier patient access to the therapy. Acceptance into the program further supports enGene’s confidence in detalimogene’s potential and aligns with enGene’s commitment to strong manufacturing practices as clinical development advances. Anticipated Milestones Update from LEGEND pivotal cohort planned for a spring 2026 medical conference. 12-month complete response data from LEGEND pivotal cohort expected in 2H 2026. Planned BLA filing for LEGEND’s pivotal cohort in the second half of 2026. First Quarter 2026 Financial Results As of January 31, 2026, cash, cash equivalents and marketable securities were $312.5 million. The Company expects that its cash, cash equivalents and marketable securities will fund operating expenses, debt obligations and capital expenditures into the second half of 2028. Total operating expenses were $31.2 million for the three months ended January 31, 2026, compared to $26.6 million for 2025. Research and development expenses increased by $2.3 million, primarily driven by increased personnel and clinical costs related to our LEGEND trial and in preparation for our planned Biologics License Application submission in the second half of 2026. General and administrative expenses increased by $2.3 million, primarily driven by personnel and facilities costs as the Company scales its general and administrative function to support the operation of a public company. For the three months ended January 31, 2026, net loss attributable to common shareholders was approximately $29.8 million, or $0.44 per share, compared to approximately $24.6 million, or $0.48 per share, for the three months ended January 31, 2025. The increase in net loss is mainly attributed to the increase in operating expenses, partially offset by net interest income earned during the period. About Non-Muscle Invasive Bladder Cancer (NMIBC) Non-muscle invasive bladder cancer (NMIBC) is a disease that poses a significant burden on both patients and clinics and has a massive economic impact on our healthcare system. NMIBC occurs when cancer cells grow in the tissues that line the interior of the bladder, but the cancer has not yet penetrated the muscle of the bladder wall. NMIBC can present as papillary outgrowths from the bladder wall, which are typically resected, or as carcinoma in situ (CIS), which consists of flat, multifocal lesions that cannot be resected. The two forms can also co-occur. About 75-80% of new bladder cancer diagnoses are NMIBC. Patients suffering from high-risk NMIBC who are unresponsive to the standard of care, Bacillus Calmette-Guérin (BCG), face high rates of disease recurrence (50-70%) and are potentially subject to full removal of the bladder (cystectomy) as a curative but life-altering next step. About Detalimogene Voraplasmid Detalimogene is a novel, investigational, non-viral gene therapy for patients with high-risk, non-muscle invasive bladder cancer (NMIBC), including Bacillus Calmette-Guérin (BCG)-unresponsive disease. It is designed to be instilled in the bladder and elicit a powerful yet localized anti-tumor immune response. Detalimogene was developed using the Company’s Dually Derivatized Oligochitosan® (DDX) platform, a technology designed to transform how gene therapies are accessed by patients and utilized by clinicians. Medicines developed with the DDX platform can potentially overcome the limitations of viral-based gene therapies, reduce complexities related to safe handling and cold storage, and streamline both manufacturing processes and administration paradigms. Detalimogene has received Regenerative Medicine Advanced Therapy (RMAT) and Fast Track designations from the U.S. Food and Drug Administration (FDA) based on its potential to address the high unmet medical need for patients with BCG-unresponsive carcinoma in situ (CIS) NMIBC with or without resected papillary tumors who are unable to undergo cystectomy. The RMAT program is intended to expedite the development and review of regenerative medicine therapies for serious or life-threatening conditions, where preliminary clinical evidence suggests potential to address unmet medical needs. Similarly, Fast Track designation is a process designed to facilitate the development and expedite the review of drugs to treat serious conditions and fill an unmet medical need. Detalimogene has also been selected to participate in the FDA’s Chemistry, Manufacturing, and Controls (CMC) Development and Readiness Pilot (CDRP) program. The FDA created the CDRP Program to facilitate CMC development for therapies with compressed clinical development timeframes based on the anticipated clinical benefits of earlier patient access to the therapy. About the LEGEND Trial Detalimogene is being evaluated in the ongoing, open-label, multi-cohort, Phase 2 LEGEND trial to establish its safety and efficacy in high-risk NMIBC. LEGEND’s pivotal cohort (Cohort 1) consists of 125 patients with high-risk, BCG-unresponsive NMIBC with CIS (with or without papillary disease) and is designed to serve as the basis of the Company’s planned Biologics License Application (BLA) filing. In addition to this pivotal cohort, LEGEND includes three additional cohorts, including NMIBC patients with CIS who are naïve to treatment with BCG (Cohort 2a); NMIBC patients with CIS who have been exposed to BCG but have not received adequate BCG treatment (Cohort 2b); and BCG-unresponsive high-risk NMIBC patients with papillary-only disease (Cohort 3). The LEGEND trial is actively enrolling patients with sites participating in the USA, Canada, Europe, and the Asia-Pacific region. About enGene enGene is a clinical-stage biotechnology company mainstreaming gene therapy through the delivery of therapeutics to mucosal tissues and other organs, with the goal of creating new ways to address diseases with high clinical needs. enGene’s lead program is detalimogene voraplasmid (also known as detalimogene, and previously EG-70) for patients with Non-Muscle Invasive Bladder Cancer (NMIBC), a disease with a high clinical burden. Detalimogene is being evaluated in the ongoing multi-cohort LEGEND Phase 2 trial, which includes a pivotal cohort studying detalimogene in high-risk, Bacillus Calmette-Guérin (BCG)-unresponsive patients with carcinoma in situ (CIS) with or without concomitant papillary disease. Detalimogene was developed using enGene’s proprietary Dually Derivatized Oligochitosan (DDX) platform, which enables penetration of mucosal tissues and delivery of a wide range of sizes and types of cargo, including DNA and various forms of RNA. To learn more, please visit enGene.com and follow us on LinkedIn, X and BlueSky. Forward-Looking Statements Certain statements contained in this press release may constitute "forward-looking statements" within the meaning of the safe harbor provisions of the Private Securities Litigation Reform Act of 1995, and "forward-looking information" within the meaning of Canadian securities laws (collectively, "forward-looking statements"). enGene’s forward-looking statements include, but are not limited to, statements regarding enGene’s management team’s expectations, hopes, beliefs, intentions, goals, or strategies regarding the future. In addition, any statements that refer to projections, forecasts or other characterizations of future events or circumstances, including any underlying assumptions, are forward-looking statements. The words "anticipate", "appear", "approximate", "believe", "continue", "could", "estimate", "expect", "foresee", "goal", "intends", "may", "might", "plan", "possible", "potential", "predict", "project", "seek", "should", "would", and similar expressions (or the negative version of such words or expressions) may identify forward-looking statements, but the absence of these words does not mean that a statement is not forward-looking. Forward-looking statements may include, for example, statements about: the Company’s plans and expectations regarding regulatory interactions and potential BLA submission for detalimogene and potential commercial launch of detalimogene, the expected period over which enGene estimates its cash and marketable securities will be sufficient to fund its current operating plan, the Company’s expectations as to the timing and anticipated results of the LEGEND study, including the timing of preliminary data or other updates, the CDRP program and its potential benefits, the RMAT designation for detalimongene and its potential benefits, the future development of detalimogene, the potential benefits of detalimogene, including its ability to become a first line therapy in BCG-unresponsive NMIBC and its attractiveness to urologists, additional loan proceeds being available to the Company under the Hercules debt facility subject to satisfaction of certain terms and conditions, and the potential benefits of medicines developed with the DDX platform. Such statements are subject to numerous important factors, risks and uncertainties, many of which are beyond enGene's control, that may cause actual events or results to differ materially from enGene's current expectations. For example, there can be no guarantee that detalimogene will successfully complete necessary clinical development phases, including achieving positive results in the pivotal cohort of the LEGEND study, or that those results or any feedback from regulatory authorities will ultimately lead to BLA submission for, and the approval of, detalimogene. Management's expectations and, therefore, any forward-looking statements in this press release could also be affected by risks, uncertainties and assumptions relating to a number of other factors, which could cause the Company’s actual results, performance or achievements to differ materially from those expressed or implied by the forward-looking statements, including, without limitation, the inability of preliminary clinical data to predict the final results of the trial, changes in the results from enGene’s clinical trials, including due to new data collected from the ongoing LEGEND study or future studies, subsequent analysis of existing data, and audit and verification procedures; the content and timing of decisions made by the FDA and other regulatory authorities; the Company’s ability to recruit and retain qualified scientific and management personnel, establish clinical trial sites and enroll patients in its clinical trials, execute on the Company’s clinical development plans; and ability to secure regulatory approval on anticipated timelines, and other risks and uncertainties detailed in filings with Canadian securities regulators on SEDAR+ and with the U.S. Securities and Exchange Commission ("SEC") on EDGAR, including those described in the "Risk Factors" section of the Company’s Annual Report on Form 10-K for the fiscal year ended October 31, 2025 (copies of which may be obtained at www.sedarplus.ca or www.sec.gov). You should not place undue reliance on any forward-looking statements, which speak only as of the date on which they are made. enGene anticipates that subsequent events and developments will cause enGene’s assessments to change. While enGene may elect to update these forward-looking statements at some point in the future, enGene specifically disclaims any obligation to do so, unless required by applicable law. Nothing in this press release should be regarded as a representation by any person that the forward-looking statements set forth herein will be achieved or that any of the contemplated results of such forward-looking statements will be achieved. View source version on businesswire.com: https://www.businesswire.com/news/home/20260309831252/en/ Contacts Media Contact: [email protected] Investor Contact: [email protected]

Completed enrollment in LEGEND’s pivotal cohort with 125 patients in high-risk, BCG-unresponsive NMIBC with carcinoma in situ Reported preliminary 6-month complete response rate (62%) in pivotal cohort patients enrolled under amended LEGEND protocol enGene selected for FDA’s CDRP Program to support CMC readiness Biologic License Application (BLA) submission for detalimogene planned for 2H 2026 Cash and marketable securities plus proceeds from November financing expected to provide cash runway into 2H 2028 BOSTON & MONTREAL, December 22, 2025--(BUSINESS WIRE)--enGene Holdings Inc. (Nasdaq: ENGN, "enGene" or the "Company"), a clinical-stage, non-viral genetic medicines company, today announced its financial results for the full year ended October 31, 2025, and provided a business update. "We are closing 2025 in a position of strength: enrollment in LEGEND's pivotal cohort is complete and the recent data update from the LEGEND pivotal cohort supports an emerging, competitive profile for the use of detalimogene as the first choice therapy in BCG-unresponsive NMIBC if approved," said Ron Cooper, President and Chief Executive Officer. "With recent acceptance into FDA’s CDRP program and a cash position of $342.4 million, extending our runway into the second half of 2028, we are entering the new year laser-focused on scaling our organization in preparation for our planned BLA filing in the second half of 2026 and a potential approval in 2027." Recent Corporate Updates LEGEND pivotal cohort update: In November, the Company reported updated preliminary data from LEGEND’s pivotal cohort for patients who were enrolled following a protocol amendment that was implemented in the fourth quarter of 2024 ("post-amendment patients"). The preliminary analysis of the post-amendment patients with at least one post-baseline disease assessment included 62 patients at 3 months and 37 patients at 6 months. Data from these patients demonstrated: 63% complete response (CR) rate at any time (n=62); 56% CR rate at 3 months (n=62); 62% CR rate at 6 months (n=37), including 4 patients who successfully converted to CR post reinduction; and All 5 patients who completed the 9-month assessment had a CR. The Company completed enrollment of 125 patients in the pivotal cohort, exceeding its target by 25%. Data from these patients demonstrated a generally favorable tolerability profile: 42% of patients experienced a treatment-related adverse event (TRAE); 1.6% of patients experienced dose interruptions due to TRAEs; and 0.8% of patients experienced dose discontinuations due to TRAEs. The Company continues to believe that detalimogene’s emerging profile supports its potential first line use in patients with high-risk, BCG-unresponsive non-muscle invasive bladder cancer with carcinoma in situ (CIS). Additional LEGEND cohort updates: In conjunction with its November data update for LEGEND’s pivotal cohort, the Company provided an enrollment update for LEGEND’s three additional cohorts: Cohort 2a, evaluating detalimogene in patients with high-risk NMIBC with CIS who are naïve to treatment with BCG, has enrolled 30 patients. Cohort 2b, evaluating detalimogene in patients with high-risk, NMIBC with CIS who have been exposed to BCG but have not received adequate BCG treatment, has enrolled 45 patients. Cohort 3, evaluating detalimogene in BCG-unresponsive patients with high-risk, papillary-only NMIBC, has enrolled 36 patients. Successful completion of public offering: In November, the Company successfully closed an underwritten public offering of its common shares and pre-funded warrants at an offering price of $8.50 per share and $8.4999 per pre-funded warrant. The offering totaled $140.1 million in net proceeds, following the full exercise of the underwriters’ option to purchase additional shares. Development and Readiness Pilot (CDRP) Program: In November, the Company was selected as one of nine companies to participate in FDA’s Chemistry, Manufacturing, and Controls (CMC) Development and Readiness Pilot (CDRP) program. The FDA created the CDRP Program to facilitate CMC development for therapies with compressed clinical development timeframes based on the anticipated clinical benefits of earlier patient access to the therapy. The initiative is designed to promote earlier and more structured engagement between sponsors and the FDA on CMC development strategies, and since its inception, has led to increased collaboration with the FDA so sponsors can confidently scale up manufacturing capacity while clinical development is ongoing. Acceptance into the program further supports enGene’s confidence in detalimogene’s potential and aligns with enGene’s commitment to strong manufacturing practices as clinical development advances. Key executive hire: In September, enGene announced the appointment of Hussein Sweiti, M.D., MSc, as Chief Medical Officer. Dr. Sweiti is a surgical oncologist and physician-scientist with more than 15 years of experience spanning clinical practice, oncology clinical research, global drug development, regulatory submissions, and medical affairs. He most recently served as Global Medical Head, Oncology Clinical Development at Johnson & Johnson (J&J), where he led end-to-end clinical strategy and execution for the company’s bladder cancer portfolio. He was intimately involved in U.S. Food and Drug Administration (FDA) interactions that culminated in J&J’s FDA approval in high-risk, BCG-unresponsive non-muscle invasive bladder cancer (NMIBC) earlier this month. Anticipated Milestones Following discussion with the FDA on its statistical analysis plan and the accumulation of sufficient 12-month CR data points, enGene expects to provide a data update on the LEGEND trial’s pivotal cohort in the second half of 2026. Planned BLA filing for LEGEND’s pivotal cohort in the second half of 2026. Fourth Quarter 2025 Financial Results As of October 31, 2025, cash, cash equivalents and marketable securities were $202.3 million. An additional $140.1 million in net proceeds was raised during a public offering in November. The Company expects that its cash and cash equivalents together with the net proceeds from the November financing will fund operating expenses, debt obligations and capital expenditures into the second half of 2028. Full Year Financial Results ended October 31, 2025 Total operating expenses were $123.2 million for the full year ended October 31, 2025, compared to $62.3 million for 2024. Research and development expenses increased by $56.2 million, primarily driven by increased manufacturing, personnel and clinical costs related to our LEGEND trial and in preparation for our planned Biologics License Application submission in the second half of 2026. General and administrative expenses increased by $4.7 million, primarily driven by personnel and facilities costs as the Company scales its general and administrative function to support the operation of a public company. For the full year ended October 31, 2025, net loss attributable to common shareholders was approximately $117.3 million, or $2.29 per share, compared to approximately $55.1 million, or $1.46 per share, for the full year 2024. The increase in net loss is mainly attributed to the increase in operating expenses, partially offset by net interest income earned during the period. About Non-Muscle Invasive Bladder Cancer (NMIBC) Non-muscle invasive bladder cancer (NMIBC) is a disease that poses a significant burden on both patients and clinics and has a massive economic impact on our healthcare system. NMIBC occurs when cancer cells grow in the tissues that line the interior of the bladder, but the cancer has not yet penetrated the muscle of the bladder wall. NMIBC can present as papillary outgrowths from the bladder wall, which are typically resected, or as carcinoma in situ (CIS), which consists of flat, multifocal lesions that cannot be resected. The two forms can also co-occur. About 75-80% of new bladder cancer diagnoses are NMIBC. Patients suffering from high-risk NMIBC who are unresponsive to the standard of care, Bacillus Calmette-Guérin (BCG), face high rates of disease recurrence (50-70%) and are potentially subject to full removal of the bladder (cystectomy) as a curative but life-altering next step. About Detalimogene Voraplasmid Detalimogene is a novel, investigational, non-viral gene therapy for patients with high-risk, non-muscle invasive bladder cancer (NMIBC), including Bacillus Calmette-Guérin (BCG)-unresponsive disease. It is designed to be instilled in the bladder and elicit a powerful yet localized anti-tumor immune response. Detalimogene was developed using the Company’s Dually Derivatized Oligochitosan® (DDX) platform, a technology designed to transform how gene therapies are accessed by patients and utilized by clinicians. Medicines developed with the DDX platform can potentially overcome the limitations of viral-based gene therapies, reduce complexities related to safe handling and cold storage, and streamline both manufacturing processes and administration paradigms. Detalimogene has received Regenerative Medicine Advanced Therapy (RMAT) and Fast Track designations from the U.S. Food and Drug Administration (FDA) based on its potential to address the high unmet medical need for patients with BCG-unresponsive carcinoma in situ (CIS) NMIBC with or without resected papillary tumors who are unable to undergo cystectomy. The RMAT program is intended to expedite the development and review of regenerative medicine therapies for serious or life-threatening conditions, where preliminary clinical evidence suggests potential to address unmet medical needs. Similarly, Fast Track designation is a process designed to facilitate the development and expedite the review of drugs to treat serious conditions and fill an unmet medical need. Detalimogene has also been selected to participate in the FDA’s Chemistry, Manufacturing, and Controls (CMC) Development and Readiness Pilot (CDRP) program. The FDA created the CDRP Program to facilitate CMC development for therapies with compressed clinical development timeframes based on the anticipated clinical benefits of earlier patient access to the therapy. About the LEGEND Trial Detalimogene is being evaluated in the ongoing, open-label, multi-cohort, Phase 2 LEGEND trial to establish its safety and efficacy in high-risk NMIBC. LEGEND’s pivotal cohort (Cohort 1) consists of 125 patients with high-risk, BCG-unresponsive NMIBC with CIS (with or without papillary disease) and is designed to serve as the basis of the Company’s planned Biologics License Application (BLA) filing. In addition to this pivotal cohort, LEGEND includes three additional cohorts, including NMIBC patients with CIS who are naïve to treatment with BCG (Cohort 2a); NMIBC patients with CIS who have been exposed to BCG but have not received adequate BCG treatment (Cohort 2b); and BCG-unresponsive high-risk NMIBC patients with papillary-only disease (Cohort 3). The LEGEND trial is actively enrolling patients with sites participating in the USA, Canada, Europe, and the Asia-Pacific region. About enGene enGene is a clinical-stage biotechnology company mainstreaming gene therapy through the delivery of therapeutics to mucosal tissues and other organs, with the goal of creating new ways to address diseases with high clinical needs. enGene’s lead program is detalimogene voraplasmid (also known as detalimogene, and previously EG-70) for patients with Non-Muscle Invasive Bladder Cancer (NMIBC), a disease with a high clinical burden. Detalimogene is being evaluated in the ongoing multi-cohort LEGEND Phase 2 trial, which includes a pivotal cohort studying detalimogene in high-risk, Bacillus Calmette-Guérin (BCG)-unresponsive patients with carcinoma in situ (CIS) with or without concomitant papillary disease. Detalimogene was developed using enGene’s proprietary Dually Derivatized Oligochitosan (DDX) platform, which enables penetration of mucosal tissues and delivery of a wide range of sizes and types of cargo, including DNA and various forms of RNA. To learn more, please visit enGene.com and follow us on LinkedIn, X and BlueSky. Forward-Looking Statements Certain statements contained in this press release may constitute "forward-looking statements" within the meaning of the safe harbor provisions of the Private Securities Litigation Reform Act of 1995, and "forward-looking information" within the meaning of Canadian securities laws (collectively, "forward-looking statements"). enGene’s forward-looking statements include, but are not limited to, statements regarding enGene’s management team’s expectations, hopes, beliefs, intentions, goals, or strategies regarding the future. In addition, any statements that refer to projections, forecasts or other characterizations of future events or circumstances, including any underlying assumptions, are forward-looking statements. The words "anticipate", "appear", "approximate", "believe", "continue", "could", "estimate", "expect", "foresee", "goal", "intends", "may", "might", "plan", "possible", "potential", "predict", "project", "seek", "should", "would", and similar expressions (or the negative version of such words or expressions) may identify forward-looking statements, but the absence of these words does not mean that a statement is not forward-looking. Forward-looking statements may include, for example, statements about: the expected period over which enGene estimates its cash and marketable securities will be sufficient to fund its current operating plan, the CDRP program and its potential benefits, the future development of detalimogene, the potential benefits of detalimogene, including its ability to become a first line therapy in BCG-unresponsive NMIBC and its attractiveness to urologists, plans regarding regulatory interactions and potential BLA submission for detalimogene, and the potential benefits of medicines developed with the DDX platform. Such statements are subject to numerous important factors, risks and uncertainties, many of which are beyond enGene's control, that may cause actual events or results to differ materially from enGene's current expectations. For example, there can be no guarantee that detalimogene will successfully complete necessary clinical development phases, including achieving positive results in the pivotal cohort of the LEGEND study, or that those results or any feedback from regulatory authorities will ultimately lead to BLA submission for, and the approval of, detalimogene. Management's expectations and, therefore, any forward-looking statements in this press release could also be affected by risks, uncertainties and assumptions relating to a number of other factors, which could cause the Company’s actual results, performance or achievements to differ materially from those expressed or implied by the forward-looking statements, including, without limitation, the inability of preliminary clinical data to predict the final results of the trial, changes in the results from enGene’s clinical trials, including due to new data collected from the ongoing LEGEND study or future studies, subsequent analysis of existing data, and audit and verification procedures; the content and timing of decisions made by the FDA and other regulatory authorities; the Company’s ability to recruit and retain qualified scientific and management personnel, establish clinical trial sites and enroll patients in its clinical trials, execute on the Company’s clinical development plans; and ability to secure regulatory approval on anticipated timelines, and other risks and uncertainties detailed in filings with Canadian securities regulators on SEDAR+ and with the U.S. Securities and Exchange Commission ("SEC") on EDGAR, including those described in the "Risk Factors" section of the Company’s Annual Report on Form 10-K for the fiscal year ended October 31, 2025 (copies of which may be obtained at www.sedarplus.ca or www.sec.gov). You should not place undue reliance on any forward-looking statements, which speak only as of the date on which they are made. enGene anticipates that subsequent events and developments will cause enGene’s assessments to change. While enGene may elect to update these forward-looking statements at some point in the future, enGene specifically disclaims any obligation to do so, unless required by applicable law. Nothing in this press release should be regarded as a representation by any person that the forward-looking statements set forth herein will be achieved or that any of the contemplated results of such forward-looking statements will be achieved. View source version on businesswire.com: https://www.businesswire.com/news/home/20251222676164/en/ Contacts Media Contact: [email protected] Investor Contact: [email protected]

enGene Holdings Inc. recently reported additional positive preliminary data from its Phase 2 LEGEND trial, highlighting a 62% complete response rate at six months for detalimogene voraplasmid in patients with high-risk, BCG-unresponsive non-muscle invasive bladder cancer. The updated trial enrolled 125 patients, surpassing original targets, and enGene plans to file for regulatory approval in the second half of 2026 for this new gene therapy approach. We'll explore how these encouraging clinical results, especially the high response rates, contribute to enGene Holdings' evolving investment narrative. These 13 companies survived and thrived after COVID and have the right ingredients to survive Trump's tariffs. Discover why before your portfolio feels the trade war pinch. For enGene Holdings, the central case for owning shares hinges on the belief that its gene therapy candidate, detalimogene voraplasmid, can transform care for high-risk, BCG-unresponsive non-muscle invasive bladder cancer. The company’s recent announcement of robust Phase 2 clinical results, a 62% complete response rate at six months, appears to have boosted investor enthusiasm, as reflected by the stock’s rapid surge and a raft of analyst price target upgrades. This milestone potentially shifts the near-term catalyst from a lengthy clinical wait to anticipation around the planned FDA filing in late 2026. However, the follow-on equity offering adds short-term dilution risk, and with enGene still unprofitable and burning cash, uncertainty around future funding and execution remains significant. The latest data may improve the risk/reward profile but does not erase the fundamental business challenges facing pre-revenue biotech firms. However, the funding and dilution risks are still very real concerns investors should be aware of. enGene Holdings' shares have been on the rise but are still potentially undervalued. Find out how large the opportunity might be. Only one fair value estimate from the Simply Wall St Community pegs enGene at US$23.70, a figure well above current prices. Against a backdrop of clinical milestones and capital raises, your outlook could vary sharply, so it’s worth exploring a range of investor viewpoints before making up your mind. Explore another fair value estimate on enGene Holdings - why the stock might be worth just $23.70! Disagree with this assessment? Create your own narrative in under 3 minutes - extraordinary investment returns rarely come from following the herd. A great starting point for your enGene Holdings research is our analysis highlighting 1 key reward and 3 important warning signs that could impact your investment decision. Our free enGene Holdings research report provides a comprehensive fundamental analysis summarized in a single visual - the Snowflake - making it easy to evaluate enGene Holdings' overall financial health at a glance. Our daily scans reveal stocks with breakout potential. Don't miss this chance: Uncover the next big thing with financially sound penny stocks that balance risk and reward. We've found 14 US stocks that are forecast to pay a dividend yield of over 6% next year. See the full list for free. Find companies with promising cash flow potential yet trading below their fair value. This article by Simply Wall St is general in nature. We provide commentary based on historical data and analyst forecasts only using an unbiased methodology and our articles are not intended to be financial advice. It does not constitute a recommendation to buy or sell any stock, and does not take account of your objectives, or your financial situation. We aim to bring you long-term focused analysis driven by fundamental data. Note that our analysis may not factor in the latest price-sensitive company announcements or qualitative material. Simply Wall St has no position in any stocks mentioned. Companies discussed in this article include ENGN. Have feedback on this article? Concerned about the content? Get in touch with us directly. Alternatively, email [email protected]

Achieved target enrollment milestone for LEGEND trial pivotal cohort in high-risk BCG unresponsive NMIBC with carcinoma in situ LEGEND’s pivotal cohort data update planned for 4Q 2025 Detalimogene granted Regenerative Medicine Advanced Therapy (RMAT) designation by FDA Biologic License Application (BLA) submission planned for 2H 2026 Cash and marketable securities of $224.9 million expected to provide runway into 2027 BOSTON & MONTREAL, September 11, 2025--(BUSINESS WIRE)--enGene Holdings Inc. (Nasdaq: ENGN, "enGene" or the "Company"), a clinical-stage, non-viral gene therapy company, today announced its financial results for the third quarter ended July 31, 2025, and provided a business update. "Reaching target enrollment in LEGEND’s pivotal Cohort 1 and securing RMAT designation are important milestones that mark our continued momentum," said Ron Cooper, Chief Executive Officer of enGene. "We look forward to providing a data update from the LEGEND pivotal cohort later this year. These advances bring us closer to our planned BLA filing in 2026 with the ultimate goal of delivering detalimogene to patients as a therapy designed for efficacy, safety, and ease-of-use." Recent Corporate Updates LEGEND study enrollment update: The Company announced that it achieved its target enrollment milestone of 100 patients with high-risk, BCG-unresponsive NMIBC carcinoma in-situ (CIS) with or without concomitant papillary disease for the pivotal cohort of its ongoing, open-label, multi-cohort Phase 2 LEGEND trial of detalimogene. Patients in the screening process remain eligible for potential enrollment in Cohort 1. Detalimogene granted RMAT designation: The Company announced that the U.S. Food and Drug Administration (FDA) granted Regenerative Medicine Advanced Therapy (RMAT) designation to detalimogene voraplasmid for the treatment of high-risk (HR), Bacillus Calmette-Guérin (BCG)-unresponsive, non-muscle invasive bladder cancer (NMIBC) with carcinoma in situ (CIS) based on previously disclosed data from the ongoing LEGEND trial. This designation provides enGene with several regulatory advantages, including early and frequent engagement with the FDA and the potential for rolling submission and priority review. Detalimogene was also granted Fast Track designation from the FDA in November 2020. Key board and management appointments: The Company announced the appointment of Philip Astley-Sparke, William Grossman, M.D., Ph.D., and Michael Heffernan R.Ph., to its Board of Directors, and the promotion of Matthew Boyd to Chief Regulatory Officer, Jill Buck to Chief Development Officer, and Katherine Chan, M.D., M.P.H. to Executive Director, Urology Clinical Lead. Their combined experience across gene therapy, oncology, urology, clinical development, and global product launches will support enGene’s strategic transition toward its planned commercialization of detalimogene. Anticipated Milestones Updated preliminary data from LEGEND trial’s pivotal cohort in 4Q 2025. Trial in progress updates from LEGEND’s additional cohorts, including HR-NMIBC patients with CIS who are naïve to treatment with BCG (Cohort 2a); HR-NMIBC patients with CIS who have been exposed to BCG but have not received adequate BCG treatment (Cohort 2b); and BCG-unresponsive HR-NMIBC patients with papillary-only disease (Cohort 3), in 4Q 2025. Planned BLA filing for LEGEND’s pivotal cohort in 2H 2026. Third Quarter 2025 Financial Results As of July 31, 2025, cash, cash equivalents and marketable securities were $224.9 million. The Company expects that its existing cash, cash equivalents and marketable securities will fund operating expenses, debt obligations and capital expenditures into 2027. Three Months ended July 31, 2025 Total operating expenses were $29.9 million for the three months ended July 31, 2025, compared to $16.8 million for the three months ended July 31, 2024. Research and development expenses increased by $11.0 million, mainly due to increasing manufacturing and clinical costs related to the pivotal cohort of our LEGEND study and personnel-related costs. General and administrative expenses increased by $2.2 million, primarily driven by increased personnel-related expense to support the operation of a public company and increased reliance on professional services to support the Company’s preparations for potential commercialization. For the three months ended July 31, 2025, net loss attributable to common shareholders was approximately $28.9 million, or $0.57 per share, compared to approximately $14.1 million, or $0.32 per share, for the same period for the three months ended July 31, 2024. The increase in net loss is mainly attributed to the increase in operating expenses, partially offset by net interest income earned during the period. About Non-Muscle Invasive Bladder Cancer (NMIBC) Non-muscle invasive bladder cancer (NMIBC) is a disease that poses a significant burden on both patients and clinics and has a massive economic impact on our healthcare system. NMIBC occurs when cancer cells grow in the tissues that line the interior of the bladder, but the cancer has not yet penetrated the muscle of the bladder wall. NMIBC can present as papillary outgrowths from the bladder wall, which are typically resected, or as carcinoma in situ (CIS), which consists of flat, multifocal lesions that cannot be resected. The two forms can also co-occur. About 75-80% of new bladder cancer diagnoses are NMIBC. Patients suffering from high-risk NMIBC who are unresponsive to the standard of care, Bacillus Calmette-Guérin (BCG), face high rates of disease recurrence (50-70%) and are potentially subject to full removal of the bladder (cystectomy) as a curative but life-altering next step. About Detalimogene Voraplasmid Detalimogene is a novel, investigational, non-viral gene therapy for patients with high-risk, non-muscle invasive bladder cancer (NMIBC), including Bacillus Calmette-Guérin (BCG)-unresponsive disease. It is designed to be instilled in the bladder and elicit a powerful yet localized anti-tumor immune response. Detalimogene was developed using the Company’s Dually Derivatized Oligochitosan® (DDX) platform, a technology designed to transform how gene therapies are accessed by patients and utilized by clinicians. Medicines developed with the DDX platform can potentially overcome the limitations of viral-based gene therapies, reduce complexities related to safe handling and cold storage, and streamline both manufacturing processes and administration paradigms. Detalimogene has received Regenerative Medicine Advanced Therapy (RMAT) and Fast Track designations from the U.S. Food and Drug Administration (FDA) based on its potential to address the high unmet medical need for patients with BCG-unresponsive carcinoma in situ (CIS) NMIBC with or without resected papillary tumors who are unable to undergo cystectomy. The RMAT program is intended to expedite the development and review of regenerative medicine therapies for serious or life-threatening conditions, where preliminary clinical evidence suggests potential to address unmet medical needs. Similarly, Fast Track designation is a process designed to facilitate the development and expedite the review of drugs to treat serious conditions and fill an unmet medical need. About the LEGEND Trial Detalimogene is being evaluated in the ongoing, open-label, multi-cohort, Phase 2 LEGEND trial to establish its safety and efficacy in high-risk NMIBC. LEGEND’s pivotal cohort (Cohort 1) consists of approximately 100 patients with high-risk, BCG-unresponsive NMIBC with CIS (with or without papillary disease) and is designed to serve as the basis of the Company’s planned Biologics License Application (BLA) filing. In addition to this pivotal cohort, LEGEND includes three additional cohorts, including NMIBC patients with CIS who are naïve to treatment with BCG (Cohort 2a); NMIBC patients with CIS who have been exposed to BCG but have not received adequate BCG treatment (Cohort 2b); and BCG-unresponsive high-risk NMIBC patients with papillary-only disease (Cohort 3). The LEGEND trial is actively enrolling patients with sites participating in the USA, Canada, Europe, and the Asia-Pacific region. About enGene enGene is a clinical-stage biotechnology company mainstreaming gene therapy through the delivery of therapeutics to mucosal tissues and other organs, with the goal of creating new ways to address diseases with high clinical needs. enGene’s lead program is detalimogene voraplasmid (also known as detalimogene, and previously EG-70) for patients with Non-Muscle Invasive Bladder Cancer (NMIBC), a disease with a high clinical burden. Detalimogene is being evaluated in the ongoing multi-cohort LEGEND Phase 2 trial, which includes a pivotal cohort studying detalimogene in high-risk, Bacillus Calmette-Guérin (BCG)-unresponsive patients with carcinoma in situ (CIS) with or without concomitant papillary disease. Detalimogene was developed using enGene’s proprietary Dually Derivatized Oligochitosan (DDX) platform, which enables penetration of mucosal tissues and delivery of a wide range of sizes and types of cargo, including DNA and various forms of RNA. To learn more, please visit enGene.com and follow us on LinkedIn, X and BlueSky. Forward-Looking Statements Certain statements contained in this press release may constitute "forward-looking statements" within the meaning of the safe harbor provisions of the Private Securities Litigation Reform Act of 1995, and "forward-looking information" within the meaning of Canadian securities laws (collectively, "forward-looking statements"). enGene’s forward-looking statements include, but are not limited to, statements regarding enGene’s management teams’ expectations, hopes, beliefs, intentions, goals, or strategies regarding the future. In addition, any statements that refer to projections, forecasts or other characterizations of future events or circumstances, including any underlying assumptions, are forward-looking statements. The words "anticipate", "appear", "approximate", "believe", "continue", "could", "estimate", "expect", "foresee", "intends", "may", "might", "plan", "possible", "potential", "predict", "project", "seek", "should", "would", and similar expressions (or the negative version of such words or expressions) may identify forward-looking statements, but the absence of these words does not mean that a statement is not forward-looking. Forward-looking statements may include, for example, statements about: the Company’s expectations as to the timing and anticipated results of the LEGEND study, including the timing of preliminary data or other updates, the Company’s expectations regarding the timing of the planned BLA submission to the Food and Drug Administration, the Company’s expectations regarding over-enrollment in the pivotal cohort of the LEGEND study, the Company’s expectations regarding the RMAT designation and its impact on the development and/or regulatory review of detalimogene, the potential benefits of detalimogene, the potential benefits of medicines developed with the DDX platform, and the expected period over which the Company estimates its cash and marketable securities will be sufficient to fund our current operating plan. Many factors, risks, uncertainties and assumptions could cause the Company’s actual results, performance or achievements to differ materially from those expressed or implied by the forward-looking statements, including, without limitation, the Company’s ability to recruit and retain qualified scientific and management personnel, establish clinical trial sites and enroll patients in its clinical trials, execute on the Company’s clinical development plans and ability to secure regulatory approval on anticipated timelines, and other risks and uncertainties detailed in filings with Canadian securities regulators on SEDAR+ and with the U.S. Securities and Exchange Commission ("SEC") on EDGAR, including those described in the "Risk Factors" section of the Company’s Annual Report on Form 10-K for the fiscal year ended October 31, 2024 (copies of which may be obtained at www.sedarplus.ca or www.sec.gov). You should not place undue reliance on any forward-looking statements, which speak only as of the date on which they are made. enGene anticipates that subsequent events and developments will cause enGene’s assessments to change. While enGene may elect to update these forward-looking statements at some point in the future, enGene specifically disclaims any obligation to do so, unless required by applicable law. Nothing in this press release should be regarded as a representation by any person that the forward-looking statements set forth herein will be achieved or that any of the contemplated results of such forward-looking statements will be achieved. View source version on businesswire.com: https://www.businesswire.com/news/home/20250911246083/en/ Contacts Media Contact: [email protected] Investor Contact: [email protected]

Additional preliminary data from ongoing LEGEND study of detalimogene in pivotal cohort of BCG-unresponsive NMIBC with CIS anticipated in 2H 2025 Biologics License Application (BLA) filing planned for mid-2026 remains on track EMA Scientific Advice completed; Indicated data could be suitable for a Contingent Marketing Authorization Application Cash and marketable securities of $251.5 million expected to provide runway into 2027 BOSTON & MONTREAL, June 12, 2025--(BUSINESS WIRE)--enGene Holdings Inc. (Nasdaq: ENGN, or "enGene" or the "Company"), a clinical-stage, non-viral genetic medicines company, today announced its financial results for the second quarter ended April 30, 2025, and provided a business update. "We have seen strong enrollment in the pivotal cohort of our LEGEND study," said Ron Cooper, Chief Executive Officer of enGene. "This positions us to stay on track for our planned trial updates across all cohorts in the second half of 2025 and a potential BLA filing in mid-2026, advancing our goal to introduce a novel, non-viral therapy that could redefine treatment for patients with high-risk non-muscle invasive bladder cancer." Recent Corporate Updates Key executive hires and management appointments: In May 2025, the Company announced the appointment of Amy Pott as Chief Global Commercialization Officer. Ms. Pott joined enGene from Astellas Pharma, where she most recently served as Senior Vice President, Strategic Brand Marketing, Ophthalmics and Rare Diseases, and previously as Head of Commercial, Gene Therapies. She will serve as the Company’s first dedicated executive for commercialization planning and execution. LEGEND study enrollment update: Over the course of the first and second quarters of 2025, the Company expanded its clinical footprint for the LEGEND study with the addition of trial sites in Europe and Asia. The pivotal cohort evaluating detalimogene voraplasmid (also known as detalimogene, and previously EG-70) in high-risk, Bacillus Calmette-Guérin (BCG)-unresponsive non-muscle invasive bladder cancer (NMIBC) with carcinoma in situ (CIS) remains on track for our planned BLA in mid-2026. The Company expects to provide an update from LEGEND’s pivotal cohort in the second half of 2025. European Medicines Agency (EMA) Scientific Advice: The Company shared detalimogene preclinical and clinical data through the EMA Scientific Advice process. During the dialogue, EMA indicated that it broadly agrees that these data could be suitable for a Conditional Marketing Authorization Application (CMA) submission for detalimogene in BCG-unresponsive NMIBC with CIS assuming a positive benefit-risk ratio. BIOTECanada Gold Leaf Biotech Company of the Year Award Winner: The Biotech Company of the Year Award recognizes a company that is transforming the future of healthcare through groundbreaking advancements. The Company is proud and honored to be recognized with this distinction. Second Quarter 2025 Financial Results As of April 30, 2025, cash, cash equivalents and marketable securities were $251.5 million. The Company expects that its existing cash, cash equivalents and marketable securities will fund operating expenses, debt obligations and capital expenditures into 2027. Three Months ended April 30, 2025 Total operating expenses were $27.1 million for the three months ended April 30, 2025, compared to $17.3 million for the three months ended April 30, 2024. Research and development expenses increased by $10.4 million, mainly due to increasing manufacturing and clinical costs related to our pivotal LEGEND study and personnel-related costs. General and administrative expenses decreased by $0.5 million, primarily driven by decreased reliance on professional services to support the Company’s operation as a publicly traded company. For the three months ended April 30, 2025, net loss attributable to common shareholders was approximately $25.8 million, or $0.51 per share, compared to approximately $15.0 million, or $0.38 per share, for the same period for the three months ended April 30, 2024. The increase in net loss is mainly attributed to the increase in operating expenses, partially offset by net interest income earned during the period. About Non-Muscle Invasive Bladder Cancer (NMIBC) Non-muscle invasive bladder cancer (NMIBC) is a disease that poses a significant burden on both patients and clinics and has a massive economic impact on our healthcare system. NMIBC occurs when cancer cells grow in the tissues that line the interior of the bladder, but the cancer has not yet penetrated the muscle of the bladder wall. NMIBC can take the form of papillary outgrowths from the bladder wall, which are typically resected, or carcinoma in situ (CIS), flat, multifocal lesions that are unable to be resected, and the two can co-occur. About 75-80% of new bladder cancer diagnoses are NMIBC. Patients suffering from high-risk NMIBC who are unresponsive to the standard of care, Bacillus Calmette-Guérin (BCG), face high rates of disease recurrence (50-70%) and are subject to full removal of the bladder (cystectomy) as a curative but life-altering next step. About Detalimogene Detalimogene is a novel, investigational, non-viral genetic medicine for patients with high-risk, NMIBC, including BCG-unresponsive disease. It is designed to be instilled in the bladder and elicit a powerful yet localized anti-tumor immune response. Detalimogene was developed using the Company’s Dually Derivatized Oligochitosan® (DDX) platform, a technology designed to transform how gene therapies are accessed by patients and utilized by clinicians. Medicines developed with the DDX platform can potentially overcome the limitations of viral-based gene therapies, simplify safe handling and cold storage complexities, and streamline both manufacturing processes and administration paradigms. Detalimogene has received Fast Track designation from the U.S. Food and Drug Administration (FDA) based on its potential to address the high unmet medical need for patients with BCG-unresponsive CIS NMIBC, with or without resected papillary tumors, who are unable to undergo cystectomy. Fast Track designation is a process designed to facilitate the development and expedite the review of drugs to treat serious conditions and fill an unmet medical need. About the Pivotal LEGEND Trial Detalimogene is being evaluated in the ongoing, open-label, multi-cohort, Phase 2 LEGEND trial to establish its safety and efficacy in high-risk, NMIBC. LEGEND’s pivotal cohort (Cohort 1) consists of approximately 100 patients with high-risk, BCG-unresponsive NMIBC with CIS (with or without papillary disease) and is designed to serve as the basis of the Company’s planned Biologics License Application (BLA) filing. In addition to this pivotal cohort, LEGEND includes three additional cohorts, including NMIBC patients with CIS who are naïve to treatment with BCG (Cohort 2a); NMIBC patients with CIS who have been exposed to BCG but have not received adequate BCG treatment (Cohort 2b); and BCG-unresponsive high-risk NMIBC patients with papillary-only disease (Cohort 3). The LEGEND trial is actively enrolling patients with sites participating in the USA, Canada, Europe, and the Asia-Pacific region. About enGene enGene is a clinical-stage biotechnology company mainstreaming genetic medicines through the delivery of therapeutics to mucosal tissues and other organs, with the goal of creating new ways to address diseases with high clinical needs. enGene’s lead program is detalimogene for patients with Non-Muscle Invasive Bladder Cancer (NMIBC) – a disease with a high clinical burden. Detalimogene is being evaluated in the ongoing multi-cohort LEGEND Phase 2 study, which includes a pivotal cohort studying detalimogene in Bacillus Calmette-Guérin (BCG)-unresponsive patients with carcinoma in situ (CIS). Detalimogene was developed using enGene’s proprietary Dually Derivatized Oligochitosan (DDX) platform, which enables penetration of mucosal tissues and delivery of a wide range of sizes and types of cargo, including DNA and various forms of RNA. For more information, visit enGene.com. Forward-Looking Statements Certain statements contained in this press release may constitute "forward-looking statements" within the meaning of the safe harbor provisions of the Private Securities Litigation Reform Act of 1995, and "forward-looking information" within the meaning of Canadian securities laws (collectively, "forward-looking statements"). enGene’s forward-looking statements include, but are not limited to, statements regarding enGene’s management teams’ expectations, hopes, beliefs, intentions, goals, or strategies regarding the future. In addition, any statements that refer to projections, forecasts or other characterizations of future events or circumstances, including any underlying assumptions, are forward-looking statements. The words "anticipate", "appear", "approximate", "believe", "continue", "could", "estimate", "expect", "foresee", "intends", "may", "might", "plan", "possible", "potential", "predict", "project", "seek", "should", "would", and similar expressions (or the negative version of such words or expressions) may identify forward-looking statements, but the absence of these words does not mean that a statement is not forward-looking. Forward-looking statements may include, for example, statements about: our plans regarding the timing of our planned BLA submission to the Food and Drug Administration, our expectations as to the timing and anticipated results of the LEGEND study, including the timing of preliminary data or other updates, our expectations regarding a potential CMA submission to the EMA, our expectations regarding completion of enrollment in the LEGEND study, including the timing, the potential benefits of detalimogene, including its potential impact on the treatment landscape and attractiveness to patients and physicians, the potential benefits of medicines developed with the DDX platform and the expected period over which we estimate our cash, cash equivalents and marketable securities will be sufficient to fund our current operating plan. Many factors, risks, uncertainties and assumptions could cause the Company’s actual results, performance or achievements to differ materially from those expressed or implied by the forward-looking statements, including, without limitation, the Company’s ability to recruit and retain qualified scientific and management personnel, establish clinical trial sites and enroll patients in its clinical trials, execute on the Company’s clinical development plans and ability to secure regulatory approval on anticipated timelines, and other risks and uncertainties detailed in filings with Canadian securities regulators on SEDAR+ and with the U.S. Securities and Exchange Commission ("SEC") on EDGAR, including those described in the "Risk Factors" section of the Company’s Annual Report on Form 10-K for the fiscal year ended October 31, 2024 (copies of which may be obtained at www.sedarplus.ca or www.sec.gov). You should not place undue reliance on any forward-looking statements, which speak only as of the date on which they are made. enGene anticipates that subsequent events and developments will cause enGene’s assessments to change. While enGene may elect to update these forward-looking statements at some point in the future, enGene specifically disclaims any obligation to do so, unless required by applicable law. Nothing in this press release should be regarded as a representation by any person that the forward-looking statements set forth herein will be achieved or that any of the contemplated results of such forward-looking statements will be achieved. enGene Holdings Inc. Condensed Consolidated Statements of Operations Information (unaudited) (Amounts in thousands of USD, except share and per share data) enGene Holdings Inc. Condensed Consolidated Balance Sheet Information (unaudited) (Amounts in thousands of USD) View source version on businesswire.com: https://www.businesswire.com/news/home/20250612000678/en/ Contacts For media: [email protected] For investors: [email protected]