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DEFENCE’S ACCUTOX®AND ANTIGEN CROSS-PRESENTATION: DISCOVERY LEADS TOWARDS THE DEVELOPMENT OF A GROUDNBREAKING PLATFORM  

Vancouver, BC, Canada, October 25^th, 2023 - Defence Therapeutics Inc. (“Defence” or the “Company”), a leading Canadian biopharmaceutical company specialized in the development of immune-oncology vaccines and drug delivery technologies, is pleased to announce the discovery of a novel function for its lead anticancer injectable drug AccuTOX® in the context of cell-based cancer vaccine engineering.

The objective of the Accum® technology is to improve the accumulation of biomolecules such as antibodies, proteins or genetic material in target cells. Defence has discovered that the delivery of unconjugated Accum® exerts powerful and potent anti-cancer properties. This observation led to the engineering of AccuTOX®, a lead Accum® variant capable of halting the growth of pre-established lymphoma, melanoma and cervical cancer when co-delivered with different immune-checkpoint blockers.

The AccuTOX® mode of action summarized as follow: i) disruption of endosomal membranes, ii) production of reactive oxygen species, iii) inducing of genotoxic effect resulting in irreversible DNA damage, and iv) triggering immunogenic cell death, which can activate the immune system leading to the development of anti-tumoral immune responses. As such, AccuTOX® not only destroys cancer tumor cells from inside-out, but it can also stimulate an immune response to protect the host from subsequent tumor re-growth.

Surprisingly, transcriptomic analysis conducted on tumor cells treated with AccuTOX® unveiled yet another therapeutic and positive effect: antigen cross-presentation. This process is very important in the context of cancer immunotherapy as it will lead the team to the future design of cell-based anticancer vaccines, capable of priming CD8 T cells, which in turns can trigger cancer destruction. In fact, the Defence team has recently completed an in vitro study demonstrating how low AccuTOX® concentrations can indeed reprogram mesenchymal stromal cells to behave like antigen presenting cells akin to Defence’s lead ARM vaccine. Once validated, Defence can advance with an optimized second-generation of its ARM vaccine.           

"This recent observation is indeed exciting and groundbreaking as it demonstrates how a single agent, AccuTOX®, can be used as an anticancer injectable at a specific concentration on a target, and as an agent suitable to engineer a cell-based vaccine when used at lower concentration on additional indications", adds M. Plouffe, the CEO of Defence Therapeutics.

Additional studies are currently ongoing to further investigate the cross-presenting potency of AccuTOX®. The versatility of AccuTOX® is adaptable to various cancer indications as well as widen the scope of AccuTOX® application by providing a line of novel therapeutic products.   

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® technology, which enables precision delivery of vaccine antigens or ADCs in their intact form to target cells. 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.

Neither the CSE nor its market regulator, as that term is defined in the policies of the CSE, accepts responsibility for the adequacy or accuracy of this release.