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PRESS RELEASE

DEFENCE THERAPEUTICS SIGNS A COLLABORATION AGREEMENT WITH THE CURIE INSTITUTE FOR TESTING THE ACCUM-T-DM1 ADC THERAPEUTIC IN PDX MODELS OF BREAST CANCER

Vancouver, BC, Canada, June 29^th, 2021 - Defence Therapeutics Inc. ("Defence" or the "Company"), is pleased to announce the establishment of a collaboration with the Curie Institute (Paris, France) to evaluate the therapeutic efficacy of Accum-T-DM1 ADC in patient-derived xenograft (PDX) models of breast cancer.

The Curie Institute is a worldwide renowned center engaged leader in fundamental and applied scientific research to better serve humankind in fighting illnesses such as cancer. Their scientific team has a wide expertise in the field of medical and experimental pharmacology with PDX models of cancer.

T-DM1 (Kadcyla(R)) is currently used to treat women with metastatic HER2-positive breast cancer. The efficacy of the treatment remains limited due to sub-optimal drug delivery to tumor cells resulting in some treatment resistance, recurrence, and side effects.

The agreement between the Curie Institute and Defence Therapeutics stipulates the following objectives related to the breast cancer:

• To perform a head-to-head toxicology profile comparisons of T-DM1 versus Accum-T-DM1 in mice.
• Complete a dose escalation study in mice bearing PDX that are T-DM1 resistant.
• Conduct a complete breast cancer efficacy study on PDX mice undergoing the ADC therapy, including in 3 HER2+ and in 1 triple-negative PDX.

"The Accum^TM technology has been very efficient at enhancing protein-/or cell-based vaccination and ADCs potency. This studies objective in demonstrating enhanced efficacy and the refined treatment regiment of Accum-T-DM1, can lead to an enhanced ADC platform for the Accum^TM technology. This serves as a strong foundation for a panoply of other therapeutics endowed with limitations known to impairing their therapeutic potency. Accum^TM enhanced efficacy opens up a broad opportunity in the ADC market to address this," mentioned Sebastien Plouffe, CEO of Defence Therapeutics.

Currently, the T-DM1 regiment is long and tedious. The use of the Accum^TM in this context is expected to increase significantly the efficiency as well as to lower the treatment cycle, which would highly lower the side effects triggered by the current ADC therapies.

US Breast Cancer Antibodies immunotherapy Therapeutics Market Offers USD 20 Billion Opportunity by 2026 according to Kuick research.

About Defence:
Defence Therapeutics is a publicly-traded biotechnology company working on engineering the next generation vaccines and ADC products using its proprietary platform. The core of Defence Therapeutics platform is the ACCUM^TM technology, which enables precision delivery of vaccine antigens or ADCs in their intact form to target cells by inducing their entrapment escape. As a result, increased efficacy and potency can be reached against catastrophic illness such as cancer and infectious diseases.

For further information:
Sebastien Plouffe, President, CEO and Director
P: (514) 947-2272
Splouffe@defencetherapeutics.com
www.defencetherapeutics.com

Cautionary Statement Regarding "Forward-Looking" Information

This release includes certain statements that may be deemed "forward-looking statements". All statements in this release, other than statements of historical facts, that address events or developments that the Company expects to occur, are forward-looking statements. Forward-looking statements are statements that are not historical facts and are generally, but not always, identified by the words "expects", "plans", "anticipates", "believes", "intends", "estimates", "projects", "potential" and similar expressions, or that events or conditions "will", "would", "may", "could" or "should" occur. Although the Company believes the expectations expressed in such forward-looking statements are based on reasonable assumptions, such statements are not guarantees of future performance and actual results may differ materially from those in the forward-looking statements. Factors that could cause the actual results to differ materially from those in forward-looking statements include regulatory actions, market prices, and continued availability of capital and financing, and general economic, market or business conditions. Investors are cautioned that any such statements are not guarantees of future performance and actual results or developments may differ materially from those projected in the forward-looking statements. Forward-looking statements are based on the beliefs, estimates and opinions of the Company's management on the date the statements are made. Except as required by applicable securities laws, the Company undertakes no obligation to update these forward-looking statements in the event that management's beliefs, estimates or opinions, or other factors, should change.

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