Dr. Amie Phinney reports

DEFENCE THERAPEUTICS CEO HIGHLIGHTS RECENT PROGRESS AND OUTLINES STRATEGIC PRIORITIES IN LETTER TO SHAREHOLDERS

Defence Therapeutics Inc. has provided a letter to shareholders from president and chief executive officer Dr. Amie Phinney outlining recent corporate progress, strategic priorities and the company's path forward.

Dear shareholders,

Defence Therapeutics is entering an exciting new stage in its evolution, and I am honoured to have the opportunity to lead the company forward. My first month as CEO has been focused on deepening my understanding of our science, sharpening our strategy and identifying our highest-value opportunities. This work has reinforced my conviction that our Accum drug-delivery technology is differentiated and has significant potential to enhance a broad range of oncology therapeutics.

Defence is a biotechnology company in a somewhat atypical position: We have been publicly funded through much of the development of our technology platform. This has enabled us to retain control of our technology, access the capital needed to advance it and give investors the opportunity to join us in building a differentiated precision drug-delivery company.

Earlier this year, Defence strengthened its financial position through a successful capital raise, giving us the resources to prepare the company for its next stage of development. Since then, we have strengthened our leadership team, expanded our board of directors, made key scientific hires, invested in laboratory capabilities and accelerated our radiotherapeutics strategy.

With this foundation in place, I believe Defence is well positioned for an important period of progress and growth.

We will pursue this through two complementary paths: advancing partnered programs that evaluate and leverage the potential of Accum across next-generation biologic drugs, while building a focused pipeline of internally developed Accum-enabled therapeutics.

Sharpening our strategy

Over the past several years, our founding CEO, Sebastien Plouffe, and our scientific teams have built a broad body of work around Accum and explored its potential across multiple therapeutic applications. As Mr. Plouffe transitions into his role as executive chairman, we are fortunate to retain his experience and commitment to the company.

My responsibility as the incoming CEO is to build on that foundation while bringing increased focus to where we invest our people and capital.

This means making choices.

Biotechnology companies rarely have the resources to pursue every scientifically interesting opportunity. The companies that create lasting value identify the areas where their science provides a meaningful advantage, generate the evidence required to validate that advantage and focus resources on those opportunities.

That is the approach we are taking at Defence Therapeutics.

Our development strategy is focused on three core areas:

• Accum-enhanced ADCs (antibody-drug conjugates);
• Accum-enabled radiotherapeutics;
• Defining the path forward for our clinical-stage AccuTox program.

Establishing Accum as an ADC-enhancing technology

Antibody-drug conjugates have become one of the most important and rapidly evolving therapeutic modalities in oncology. Despite significant innovation in antibodies, targets, linkers and payloads, efficient intracellular delivery of the therapeutic payload remains an important challenge and an opportunity to further improve ADC performance.

This is the problem Accum was designed to address.

Our studies to date have demonstrated Accum's potential to improve intracellular delivery and enhance ADC activity, including the potential for greater anti-tumour activity at lower doses. Our priority now is to evaluate this potential across a broader range of ADCs.

Importantly, we do not intend to compete with ADC developers -- our objective is to enable them. We are actively engaging companies whose assets could benefit from Accum, with the goal of establishing partnerships to evaluate Accum's potential to improve their ADCs.

Our commercial objective with this program is to drive adoption of Accum through revenue-generating partnerships and licences. Over the longer term, we intend to reinvest revenue from these activities in emerging applications, including exploring Accum's potential to improve the delivery of next-generation payloads such as RNA and oligonucleotides.

Advancing Accum-enabled radiotherapeutics

Our second major area of investment is targeted radiotherapeutics, a rapidly growing field where we believe Accum can offer a differentiated approach to improving the intracellular delivery and retention of radioisotopes in tumour cells.

We recently strengthened this program with the appointment of Dr. Ryan Simms as chief operating officer and head of radiotherapeutics. Dr. Simms brings more than 20 years of radiopharmaceutical development experience and the specialized expertise needed to accelerate this program.

Over the coming year, our focus will be on generating data to evaluate where Accum may provide the greatest potential benefit and advancing the most promising Accum-enabled radiotherapeutics toward clinical development.

Defining the path forward for AccuTox

Our third priority is AccuTox, Defence's most clinically advanced asset.

Clinical development of AccuTox was paused last year as the company reassessed its development priorities and allocation of capital. Importantly, that decision did not eliminate the underlying asset or the body of preclinical work supporting it.

We are now undertaking a comprehensive review of the AccuTox program, with a particular focus on its potential positioning in melanoma.

Our objective is to determine the path that we believe has the greatest potential to create value from this asset without distracting from our core investment in Accum.

That may include monetizing the program through an outlicensing transaction, advancing it with a co-development partner or, if supported by the data and economics, reactivating it as an internal clinical program.

We will be disciplined in this assessment. AccuTox represents an important asset within Defence's portfolio, and any decision to deploy additional company capital toward clinical development will be weighed carefully against the opportunities we see in Accum.

What you can expect over the next 12 months

Over the coming 12 months, we will focus our efforts on three clear priorities:

• Identifying new ADC collaborations to evaluate Accum's potential to enhance partnered ADCs and create opportunities for broader adoption and licensing;
• Advancing our Accum-enabled radiotherapeutics strategy by generating foundational data, expanding development capabilities and progressing a focused portfolio of Accum-enabled assets toward clinical development;
• Communicating the path forward for AccuTox -- whether through partnering, outlicensing or selective reactivation of clinical development in melanoma.

Looking ahead

With a differentiated technology platform and a focused strategy, Defence is well positioned to translate years of scientific innovation into programs and partnerships that can define our future.

As a shareholder myself, I understand the importance of demonstrating progress against these objectives. I intend to communicate with you regularly -- not only about what we accomplish, but why we are making the choices we are making and how they contribute to long-term value.

Thank you for your continued confidence in Defence Therapeutics. I am tremendously excited about what lies ahead and look forward to sharing our progress with you.

Dr. Amie Phinney, PhD, MBA

President and chief executive officer of Defence Therapeutics

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 pursuing cutting-edge science and collaborating with pharma and biotech partners, Defence strives to bring transformative therapies to patients who need them most.

We seek Safe Harbor.