Mr. Sebastien Plouffe reports

DEFENCE THERAPEUTICS APPOINTS ANTIBODY DRUG CONJUGATES PIONEER DR. JOHN LAMBERT TO ITS BOARD OF DIRECTORS

Defence Therapeutics Inc. has appointed Dr. John Lambert to its board of directors, effective immediately. Dr. Lambert brings more than four decades of scientific leadership and pioneering expertise in the development of antibody-drug conjugates (ADCs), further strengthening Defence's strategic capabilities as the company advances its Accum-enabled ADC platform and partnership programs.

Dr. Lambert is internationally recognized as one of the leading experts in the ADC field. He previously served in multiple senior scientific and executive leadership roles at ImmunoGen, including chief scientific officer, executive vice-president of research and member of the executive committee. During his tenure, scientists at ImmunoGen developed ADC technologies that ultimately contributed to the Genentech/Roche therapy KADCYLA, approved in 2013 for HER2-positive breast cancer. The company also discovered the anti-CD38 antibody that became Sanofi's SARCLISA and advanced several ADC molecules into clinical development, including ELAHERE, approved for platinum-resistant ovarian cancer. ImmunoGen was subsequently acquired by AbbVie in 2024.

Prior to joining ImmunoGen in 1987, Dr. Lambert was among the first scientists recruited to the Dana-Farber Cancer Institute at Harvard Medical School to work on ImmunoGen-financed programs dedicated to developing ADCs and immunotoxins as anti-cancer therapeutics, at a time when the field was still in its infancy.

Dr. Lambert's scientific career also includes training at some of the world's most respected academic institutions. He graduated from Christ's College, University of Cambridge (UK), with a degree in natural sciences before earning a PhD in biochemistry from the University of Cambridge in 1976, where he worked on the structure of glycolytic enzymes under the supervision of Prof. Richard N. Perham. He subsequently completed postdoctoral research at the University of California, Davis, focusing on ribosome structure, and later at the University of Glasgow, Scotland, where he worked on the arom multienzyme complex.

Since 2018, Dr. Lambert has advised numerous biotechnology companies and venture capital firms on ADC technologies, development strategies and translational programs. He is the author or co-author of more than 130 peer-reviewed scientific publications and was elected fellow of the American Institute for Medical and Biological Engineering (AIMBE) in 2016.

"We are extremely proud to welcome Dr. Lambert to Defence's board of directors," said Sebastien Plouffe, chief executive officer of Defence Therapeutics. "John is one of the most respected pioneers in the ADC field and has contributed to the development of technologies and therapeutics that have had a major impact on cancer treatment worldwide. His scientific vision, leadership experience and deep understanding of ADC development will be instrumental as Defence advances its Accum platform and expands its Accum-enabled ADC programs and partnerships. Having someone of John's calibre joining our Board is a tremendous validation of the potential of our technology."

"I am excited to join Defence Therapeutics' board of directors at such an important time for the company," said Dr. John Lambert. "Defence's Accum technology represents a compelling and innovative approach to improving intracellular delivery and potentially enhancing the therapeutic performance of ADCs and other complex biologics. I look forward to working with the team and contributing to the continued advancement of the company's technology and development programs."

The company has granted 150,000 incentive stock options to Dr. Lambert, in accordance with the terms and conditions of Defence's omnibus incentive plan. The options are vested immediately and exercisable at a price of 58 cents per share for a period of five years from the date of grant.

Defence Therapeutics is actively advancing its proprietary Accum platform across multiple therapeutic applications, including ADCs and radiopharmaceuticals, with the objective of improving intracellular delivery, therapeutic efficacy and overall treatment outcomes.

About Defence Therapeutics Inc.

Defence Therapeutics is a publicly traded biotechnology company committed to making cancer treatment more effective and safer. Using its Accum precision drug delivery platform, Defence is working to enhance the potency of ADCs and other complex biologics at lower doses, with the goal of reducing side effects and improving access to advanced therapies. By pursing cutting-edge science, and collaborating with pharma and biotech partners, Defence strives to bring transformative therapies to patients who need them most.

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