Defence Therapeutics Granted CNRI-H from the Canadian Nuclear Laboratories to Accelerate the Development of Its Radio-Immuno-Conjugates Program

Vancouver, British Columbia--(Newsfile Corp. - July 24, 2024) - Defence Therapeutics Inc. (CSE: DTC) (OTCQB: DTCFF) (FSE: DTC) ("Defence" or the "Company"), a Canadian biopharmaceutical company developing novel immune-oncology vaccines and drug delivery technologies, is pleased to announce that its Canadian Nuclear Research Initiative Health ("CNRI-H") Program application was retained and approved by the Canadian Nuclear Laboratories ("CNL") to accelerate Defence's radio-immuno-conjugates project.

Defence's CNRI-H project will focus on the synthesis and evaluation of novel constructs, variations of ¹¹¹In-AccuTOX®-Trastuzumab. The objective is to demonstrate that AccuTOX® moiety is an essential modification to conventional ¹¹¹In-Trastuzumab constructs to evade an endosome entrapment and ensure nuclear localization, where ¹¹¹In will emit Auger Electrons ("AEs") to kill cancer cells, and providing a synergistic effect by unleashing AccuTOX® immune-boosting power. It is expected that these constructs will be lethal to HER2-positive cancer cells specifically and will produce high potency.

Selected AccuTOX® constructs, based on stability, solubility, and biochemical properties, will be conjugated to the trastuzumab antibody, followed by radiolabeled with ¹¹¹In, and then characterized, in vitro and in vivo, for its efficacy in killing cancer. The main goal is to identify the biologically active ¹¹¹In-AccuTOX®-Trastuzumab molecule that will be more potent to treat solid tumor resistant to current HER2-targeting therapy such as therapeutic antibodies (e.g., trastuzumab alone) and antibody-drug conjugate (e.g., Kadcyla®).

In summary, the aim of this CNRI-H collaborative project is:

1. To synthesize AccuTOX®-Trastuzumab antibody conjugates, radiolabel with ¹¹¹In, and characterize, including structure and cellular analysis (e.g. identification, drug-antibody ratio, specific activity), stability, and cytotoxic effects, in vitro.

2. To perform animal studies in rodents, in vivo, namely biodistribution, pharmacokinetic profile, and therapeutic potency, using selected ¹¹¹In-AccuTOX®-Trastuzumab constructs.

"We are proud to have this opportunity to collaborate with the Canadian Nuclear Laboratories and to advancing Defence's radio-immuno-conjugates program for the benefit of the cancer's patients. The CNL scientific team dedicated to our project is very strong and will definitely accelerate and reinforce Defence's strength in this renowned and fast-growing radiopharmaceuticals field," said Sebastien Plouffe, Chief Executive Officer of Defence Therapeutics.