Community Key Opinion Leaders (KOLs) to present on real-world clinical decision making in high-risk non-muscle invasive bladder cancer (NMIBC)

Additional discussion to focus on preclinical data supporting incorporation of a surfactant bladder rinse plus detalimogene voraplasmid into clinical development

enGene Therapeutics Inc. (NASDAQ:ENGN, "enGene" or the "Company")), a clinical-stage, non-viral genetic medicines company, today announced that it will host a webinar on Thursday, October 15, 2026 at 10:00 AM ET that will provide greater detail on the preclinical data supporting the incorporation of its surfactant bladder rinse plus detalimogene voraplasmid (detalimogene) into clinical development for Bacillus Calmette-Guérin (BCG)-unresponsive, high-risk, non-muscle invasive bladder cancer (NMIBC) with carcinoma in situ (CIS). Two community key opinion leaders (KOLs) from Colorado Urology, David J. Cahn, MD and Suzanne B. Merrill, MD, FACS, will review clinical case studies and discuss various real-world treatment considerations. To register, click here.

Surfactants have been shown to boost efficacy with other NMIBC gene therapies in preclinical models and were subsequently incorporated into clinical development of those gene therapies. enGene is currently enrolling high-risk, BCG-unresponsive NMIBC patients with CIS in an additional cohort in its ongoing LEGEND trial, which incorporates a short surfactant bladder rinse (generic name: polidocanol) prior to intravesical administration of detalimogene. Detalimogene is an investigational, non-viral gene therapy for the treatment of high-risk, NMIBC.

A live question and answer session will follow the formal presentations.

About David J. Cahn, MD

Dr. Cahn is a board-certified urologist with fellowship training in neurourology. He brings years of extensive experience to complex urological conditions that require surgical intervention. Involved with InterStim^® technology since its approval by the Food and Drug Administration (FDA) in 1998, Dr. Cahn is one of Colorado’s most experienced minimally invasive surgeons treating overactive bladder. Dr. Cahn also specializes in advanced prostate cancer while still maintaining an active general urology practice. In addition, he serves as the Medical Director for Colorado Clinical Research, leading the practice’s clinical trials program.

Dr. Cahn has been in private practice since 1998 and founded Foothills Urology in 2000, now Colorado Urology. He is a member of the Colorado Urology Executive Council.

Dr. Cahn received his medical degree from Albert Einstein College of Medicine in the Bronx, New York, and his bachelor’s degree at Wesleyan University. He completed his residency in urology at Montefiore Medical Center in the Bronx, New York, and his fellowship training in neurourology and female urology at the University of Colorado School of Medicine. He is board-certified by the American Board of Urology.

About Suzanne B. Merrill, MD, FACS

Dr. Suzanne B. Merrill is a board-certified urologist who is fellowship trained in Urologic Oncology. She specializes in the treatment of all cancers of the urinary tract, including bladder, upper tract/urothelial, kidney, prostate, testicular, adrenal, and penile cancer. Dr. Merrill utilizes robotic, minimally invasive as well as open surgical techniques to offer her patients with individualized and top-of-class treatment options. After a career in academic medicine, she transitioned to Colorado Urology where she became the bladder cancer and advanced therapeutic regional leader for the organization. In these roles, she ensures patients at Colorado Urology have access to the most cutting-edge bladder and kidney cancer FDA approved treatments as well as opportunities to engage in clinical trials that deliver highly anticipated novel therapies.

Dr. Merrill completed her bachelor’s degree with summa cum laude honors at The University of Delaware and obtained her Medical Doctorate at The University of North Carolina – Chapel Hill School of Medicine. She completed her residency at Duke University, followed by a Society of Urologic Oncology fellowship at The Mayo Clinic in Rochester, Minnesota. While at the Mayo Clinic, she also received a certificate in Translational Research. Prior to joining Colorado Urology, she was an Associate Professor of Urologic Oncology and Residency Program Director at Penn State Hershey Medical Center in Pennsylvania, where she was recognized with awards for her outstanding faculty leadership and mentorship, as well as humanism and professionalism in surgery.

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, 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, 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 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/20261013024970/en/

Media and Investor:

Lauren Hopfer

lhopfer@engene.com