CSE: DTC FSE: DTC USOTC: DTCFF PRESS RELEASE

DEFENCE THERAPEUTICS SELECTS THE BEST 8 ACCUM^TM VARIANTS TO OPTIMIZE ITS ADC THERAPEUTIC

Vancouver, BC, Canada, August 18^th, 2021 - Defence Therapeutics Inc. ("Defence" or the "Company"), is pleased to announce, that after a detailed and rigorous selection process, very strong and promising results of its bests Accum^TM variants has been identified.

Defence's has tested 43 Accum^TM variants conjugated to T-DM1 with a low conjugation ratio (1-4 Accum^TM per T-DM1) in order to select the best ones to pursue our selection of the optimized Accum-T-DM1 conjugate based on in vitro assessments. These studies highlight the additive effect of the Accum^TM technology and guide the selection of the optimal Accum-T-DM1 in vivo testing on breast and gastric cancer models.

On the 43 Accum^TM variants tested, we have selected the 8 best which will be sent this week to our collaborator at the HUS Comprehensive Cancer Center in Helsinki, Finland for the optimization of Defence's Accum-T-DM1 ADC Therapeutic. The 8 selected Accum-T-DM1 increases the potency of T-DM1 by at least 5-fold on the HER2 positive breast cancer Trastuzumab and T-DM1 resistant cell line model named JIMT-1. At concentration of 1.0 ug/ml, T-DM1 only induce approximatively 10% of cytotoxicity comparatively to Accum-T-DM1 variants that increase the cytotoxicity by 40-70%. Our Collaborator will also do a head-to-head comparison to the new ADC Enhertu(R) owned by AstraZeneca and Daiichi Sankyo. Enhertu(R) (fam-trastuzumab-deruxtecan-nxki) is a newcomer ADC designed to treat HER2 heterogeneous tumors through a bystander effect.

Defence's Accum^TM platform has been developed and tested in vitro to enhance the intracellular drug delivery on multiple ADCs that are FDA approved or under development. In that regard, Defence is also pleased to announce the commencement of a new study project to test the Accum^TM variants on the recent ADC Enhertu(R) (fam-trastuzumab-deruxtecan-nxki) owned by AstraZeneca and Daiichi Sankyo. Defence's scientific team believes the Accum^TM will increase the routing and delivery of the deruxtecan to the nucleus and consequently will increase more significantly the potency of ADC from which the drug targets the nucleus protein/process compared to T-DM1 targeting microtubule (a cytoplasmic and non-nucleus protein machinery). Deruxtecan is a small toxic drug inhibitor targeting the nuclear protein named topoisomerase I.

"The 8 selected Accum^TM variants produced very impressive results that confirms the strength and optimization of our Accum^TM platform in the ADC field of therapeutics against breast and gastric cancer. The versatility of our Accum^TM platform and variants gives us a solid competitive advantage" said Sebastien Plouffe, Chief Executive Officer of Defence Therapeutics.

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.

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.