Dr. Amie Phinney reports

DEFENCE THERAPEUTICS PROVIDES CORPORATE UPDATE AS COMPANY EXECUTES ON STRATEGIC PRIORITIES

Defence Therapeutics Inc. has provided a corporate update as the company continues to execute on the strategic priorities outlined in its recent letter to shareholders.

Since assuming the role of president and chief executive officer in August, Dr. Amie Phinney and the Defence leadership team have focused on translating the company's strategy into execution across its scientific programs, leadership and operations. Defence is prioritizing Accum-enhanced antibody drug conjugate partnerships, the in-house development of Accum-enabled radiotherapeutics and the evaluation of strategic development options for AccuTOX.

"Our recent shareholder letter set out a focused strategy for Defence and, importantly, a commitment to demonstrate progress against it," said Dr. Phinney. "We are now moving forward with that execution, strengthening the expertise supporting our priority programs, aligning leadership incentives with long-term shareholder value creation, and deploying the capital and resources needed to advance our strategy."

To this end, Dr. Svetlana Selivanova has resigned from Defence's board of directors to transition to the company's scientific advisory board, where she will deepen her scientific engagement with the company and contribute her expertise in radiopharmacology. Her appointment strengthens the scientific expertise supporting Defence's growing radiopharmaceutical program as the company advances its strategy to evaluate the potential of Accum to improve the intracellular delivery and retention of radioisotopes in tumour cells. The transition builds on Defence's strategic priority, including the appointment of Dr. Ryan Simms as chief operating officer and head of radiopharmaceutical programs, and the expansion of the company's development strategy to evaluate both alpha- and beta-emitting radioisotopes.

"We are very pleased that Svetlana will continue her work with Defence in a role that allows us to more directly leverage her scientific expertise," said Dr. Phinney.

The company also announces that its board of directors has approved the grant of an aggregate number of seven million incentive restricted stock units to Dr. Phinney, president and chief executive officer, and Sebastien Plouffe, executive chairman. The RSUs are structured as performance-based incentives tied to defined share price milestones, aligning a significant component of leadership compensation with long-term shareholder value creation.

The RSUs will be issued in five equal instalments upon the common shares of the company achieving closing prices on the Canadian Securities Exchange at or above 75 cents, $1, $1.25, $1.50 and $1.75, respectively. Each RSU entitles the holder to receive one common share of the company. The RSUs expire on Sept. 24, 2029, and remain subject to the terms of the company's omnibus incentive plan and applicable securities laws.

The company is also pleased to provide another update on its sharing agreement dated March 6, 2026, with Sorbie Bornholm LP, previously described in the company's news releases of March 9 and Feb. 27, 2026. Further to the first settlement dated Aug. 14, 2026, the company has received the second settlement in the amount of $249,696.72 as of the settlement date of Sept. 15, 2026, against 606,060 placement shares released to SBLP. As of today, 9,696,971 placement shares are held in escrow in connection with the sharing agreement, and there are 16 settlement payments remaining.

Defence remains focused on the priorities communicated to shareholders: expanding opportunities to evaluate Accum with partnered ADCs, generating foundational data and advancing its Accum-enabled radiotherapeutics programs, and determining the optimal path forward for AccuTOX. The company expects to provide further updates as these initiatives progress.

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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