Announcement PDF Percheron Therapeutics Limited ABN 41 095 060 745 ASX: PER | FSE: AWY | US OTC: ATHJY PERCHERON THERAPEUTICS CORPORATE PRESENTATION Melbourne, Australia – 1 September 2026: Percheron Therapeutics Limited (ASX: PER) (‘the Company’), an international biotechnology company focused on the development of novel therapies for oncology and rare diseases, is pleased to provide shareholders with a copy of an updated non-confidential corporate presentation providing further information on the recently announced investigator sponsored clinical trial to be conducted by Vanderbilt Health. ~ ENDS ~ About Percheron Therapeutics Limited Percheron Therapeutics Limited [ASX: PER | US OTC: PERCF] is a publicly listed biotechnology company focused on the development and commercialisation of novel therapies for oncology and rare diseases. The company’s lead program is HMBD-002, a monoclonal antibody targeting the immune checkpoint regulator, VISTA. HMBD-002 has completed a phase I clinical trial in patients with advanced cancer, which has shown the drug to be generally safe and well-tolerated, and Percheron aims to commence further clinical trials in CY2026. For more information, please contact info@PercheronTx.com. This announcement has been authorized for release to the Australian Securities Exchange by the Board of Directors. www.PercheronTx.com ASX: PER | US OTC: PERCF Advancing a Next Generation Immune Checkpoint Inhibitor into Blood Cancers Investor Update September 2026 1 Forward-Looking Statements This presentation contains forward-looking statements within the meaning of the safe-harbor provisions such as the Private Securities Litigation Reform Act of 1995. These statements do not relate strictly to historical or current facts and may be accompanied by words such as ‘could,’ ‘would,’ ‘may,’ ‘potentially,’ ‘suggest,’ ‘believes,’ ‘expects,’ ‘should,’ ‘intends,’ ‘plans,’ ‘forecasts,’ and similar words or expressions. Such statements involve substantial risks and uncertainties, not all of which may be known at the time. All statements contained in this presentation, other than statements of historical fact, including without limitation statements regarding our strategy, research and development plans, collaborations, future operations, future financial position, future revenues, projected costs, pricing, prospects, plans, and objectives of management, are forward-looking statements. Not all forward-looking statements in this presentation are explicitly identified as such. The Company does not warrant any of the forward-looking statements in this presentation, and investors are advised to interpret such statements in the context of other available sources of information and with the assistance of expert advisors as appropriate. Many factors could cause the actual results of the Company to differ materially from the results expressed or implied herein, and you should not place undue reliance on the forward-looking statements. Drug development is inherently risky, and only a small proportion of research and development programs lead to a marketed product. Factors which could change the Company’s expected outcomes include, without limitation, our ability to: advance the development of our programs, and to do so within any timelines that may be indicated herein; the safety and efficacy of our drug development candidates; our ability to replicate experimental data; the ongoing validity of patents covering our drug development candidates, and our freedom to operate under third party intellectual property; our ability to obtain necessary regulatory approvals; our ability to enter into and maintain partnerships, collaborations, and other business relationships necessary to the progression of our drug development candidates; changes in the competitive landscape pertaining to our drug development candidates; the timely availability of necessary capital to pursue our business objectives; changes in the public policy environment in one or more countries in which we operate or may seek to operate which disfavour our business; our ability to attract and retain qualified personnel; changes from anticipated levels of customer acceptance of existing and new products and services; and other factors. Although the Company believes that the expectations reflected in such forward-looking statements are reasonable, and although they reflect our current views as at the date of this presentation, there can therefore be no assurance that such expectations will prove to be correct. The Company has no obligation as a result of this presentation to pursue any specific strategy or plan outlined herein, or to deliver any specific outcome that may be implied or inferred. Any forward-looking statements contained in this presentation speak only as of the date this presentation is made, and we expressly disclaim any obligation to update any forward-looking statements, whether because of new information, future events or otherwise, except as may be required by law. 2 Executive Summary • Percheron has entered into an agreement with Vanderbilt Health (VH) to conduct a multi-centre clinical trial of HMBD-002 in patients with acute myeloid leukaemia (AML) • AML is the most common form of leukaemia, with about 20,000 patients diagnosed annually in the United States • Existing therapies are initially effective in a majority of patients, but >50% will relapse, and long-term outcomes remain challenging • VH study is an investigator-sponsored trial (IST), with Percheron’s obligations limited to a financial grant, study drug, and advisory support • Following a $2.3 million capital raise in August 2026, Percheron’s commitments associated with the AML study are fully funded • In preparation for new clinical trial work, the Company has successfully completed drug substance manufacture, with new clinical material expected to be available for shipping to sites in 2H CY2026 • Dr Michael Baker has been appointed CEO and Managing Director, commencing on 5 October 2026 • Dr James Garner has stepped down as CEO but will remain a non-executive director to provide continuity and support • World Health Organisation has selected ‘minperstobart’ as the provisional international non-proprietary name (pINN) for HMBD- 002, with confirmation during CY2027 Percheron is developing HMBD-002, a novel, mid-clinical-stage, immuno-oncology therapy with applicability to multiple forms of cancer and high combination potential 3 THE SCIENCE THE COMPANY THE OPPORTUNITY Percheron is developing HMBD-002, a next generation immune checkpoint inhibitor, with the potential to treat many forms of cancer Percheron is listed on the ASX (ASX: PER), with a market cap of ~$8 million, and cash at 30JUN26 of ~$4.1 million With phase 1 successfully completed in CY2025, Percheron aims to take HMBD-002 into an international phase 2 human trial in CY2026 HMBD-002 targets VISTA, a novel immune checkpoint, similar in many respects to PD-1, the target of Keytruda® (pembrolizumab) Previous attempts to drug VISTA have been limited by toxicity; HMBD-002 is built on a different antibody scaffold, substantially reducing potential toxicity HMBD-002 has potential as a monotherapy, but also appears synergistic with other checkpoint inhibitors such as Keytruda® The company trades at a substantial discount to ASX-listed peers, following a corporate transformation during CY2025 Enterprise value largely reflects acquisition cost of HMBD-002 (~$4.5 million), currently imputing no value to future positive data Percheron’s cash reserves and low burn imply 3.9 quarters of funding, per June 2026 Appendix 4C filing US-based phase 1 study, conducted under IND with US FDA, showed very favourable safety profile, both as monotherapy and in combination with Keytruda® (pembrolizumab) Adaptive, modular phase 2 study design can be launched with very modest cash resources and is designed to provide early validating read-outs Keytruda® patent expiry in 2028 creates substantial opportunity for novel immune checkpoint inhibitors to expand and extend US$ ~100 billion market Immune checkpoint inhibitors such as HMBD-002 work by reactivating the body’s immune response so that it can attack the tumour 4 Cancer cells Immune cells • Ordinarily, our immune system protects us against tumour cells in the same way that it protects against bacteria and viruses • Growing tumours need to inhibit the patient’s immune system to avoid being attacked by normal defences • One of the ways tumours accomplish this is via ‘immune checkpoints’ such as PD-1 (the target of Keytruda®) and VISTA (the target of HMBD-002) HMBD-002 • Immune checkpoint inhibitors such as HMBD-002 block these inhibitory signals on the surface of the cancer cell • A number of such immune checkpoint inhibitor drugs have been approved by FDA in recent years, including Keytruda®, Opdivo®, Tecentriq®, Yervoy® and others • There are not yet any commercial VISTA inhibitors, partly because the target is relatively newly discovered • Removal of the inhibitory signals allows the body’s own immune system to attack the cancer cells • The reinvigorated immune system can be potent in its own right, but can also work synergistically with other cancer treatments such as chemotherapy and radiotherapy • In some cancers, inhibiting multiple immune checkpoints is more effective than just one (e.g. PD-1 and CTLA-4 in melanoma) • In addition to making the cancer cells vulnerable to the immune system, VISTA inhibition helps to attract more immune cells into the ‘tumour microenvironment,’ potentially amplifying its effects by turning ‘cold tumours’ into ‘hot tumours’ • In particular, VISTA inhibition appears to attract myeloid cells, which are less susceptible to other immune checkpoint inhibitors HMBD-002 is arguably the most advanced VISTA antibody in clinical development, and likely the only active member of the IgG4 class 5 Program HMBD-002 CI-8993 JNJ-61610588 SNS-101 W0180 Company Isotype IgG4 IgG1 IgG1 IgG1 IgG1 Stage Phase I Complete Phase I Complete Phase I Terminated Phase I Terminated Phase I Terminated Exposure to Date 48 patients 26 patients 12 patients - 33 patients Combination Data Available Monotherapy & Combination with Pembrolizumab Monotherapy Monotherapy Monotherapy & Combination with Cemiplimab Monotherapy & Combination with Pembrolizumab Status Ongoing Inactive Discontinued Discontinued Discontinued Notes pH-sensitive antibody INDICATIVE Sources: Company filings; Clinicaltrials.gov In general, IgG1 antibodies activate antibody-dependent cellular cytotoxicity (ADCC), recruiting immune cells such as natural killer (NK) cells to destroy the target. This can be a very effective approach in cancer, but can also lead to significant toxicity, including cytokine release syndrome (CRS). Expert feedback indicates that the key challenge with other VISTA antibodies, which are almost exclusively IgG1, is that they have often proven toxic in clinical trials. HMBD-002 is an IgG4 antibody, so it blocks VISTA signalling, but does not necessarily destroy VISTA-positive cells. This is likely to make it significantly less toxic in clinical use. Acute myeloid leukaemia (AML) is the most common form of leukaemia in adults Pathology Clinical Picture • AML is a cancer of the progenitor cells which ordinarily give rise to myeloid immune cells in the blood • The cancerous cells multiply in an uncontrolled way and ‘crowd out’ healthy cells in bone marrow and blood • Common symptoms of AML include fatigue, bruising, bleeding, and infection • Untreated, AML is typically fatal within months • Approximately 20,000 patients are diagnosed annually in the US; most common in males over 60 years of age • Five-year survival is estimated at 10% - 35%, depending mainly on the general health of the patient at diagnosis Standard of Care • First-line treatment is with intensive chemotherapy. • Approximately 60-80% of patients are initially responsive. However, roughly half of those will eventually relapse. • In patients who relapse, or who are unfit for intensive chemotherapy, a range of other agents are used, including venetoclax (discovered at the Walter & Eliza Hill Institute in Melbourne, Australia) • Stem cell transplants are increasingly used in patients who are not suitable for pharmacological therapies VISTA is a highly relevant and attractive target for treatment of AML 7 Source: TK Kim et al. (2024) J Clin Invest. 134(3):e164325 VISTA is highly expressed on AML blasts VISTA expression correlates with survival in AML models Blocking VISTA improves clinical outcome in AML models High VISTA expression (n=40) Low VISTA expression (n=40) Healthy Donor AML Control VISTA Anti-VISTA antibody Control • Tumour cells express much higher levels of VISTA than those drawn from healthy donors • Tumours with high VISTA expression have a worse prognosis than those with low VISTA expression • An anti-VISTA antibody significantly slows tumour growth in an animal model of AML The study is planned to be conducted in two stages, under an open label design 8 Stage 1 Confirm dose of HMBD-002 in combination with azacitidine and venetoclax Stage 2 Identify signals of potential efficacy Expected recruitment: 29 – 38 patients Patient population: initially relapsed / refractory high- risk AML / MDS patients, with potential extension to newly-diagnosed patients in Stage 2 PRELIMINARY Venetoclax • Inhibits Bcl-2 protein, implicated in several blood cancers • Discovered at Walter & Eliza Hill Institute (Melbourne, VIC) • Global sales ~US$ 1.4 billion (2025) Azacitidine • Chemotherapy agent that impedes DNA synthesis in tumours The Percheron Board and Management Team bring extensive international experience in drug development, commercialisation, and partnering 9 Dr Charmaine Gittleson Non-Executive Chair of the Board 25 years of drug development experience, including 15-year tenure with CSL in international roles Dr Gil Price Non-Executive Director & Chair of Audit Experienced biotech executive and entrepreneur with extensive experience in drug development Dr James Garner Non-Executive Director 25-year track record of international drug development, including ten years as a public company life sciences CEO Deborah Ambrosini Chief Financial Officer & Company Secretary Over 20 years of strategic financial experience with a diverse range of ASX-listed companies Valentina Dubljevic Chief Technical Officer 20-year track record of international drug development in multinational companies Dr Eugene Kennedy Chief Medical Officer Johns Hopkins-trained cancer surgeon with over ten years of experience in immuno- oncology drug development * Dr Michael Baker Chief Executive Officer & Managing Director Scientist, investor, and company-builder, including six years with Arovella Therapeutics * Note: Dr Baker commences his appointment on 5 October 2026 10 Percheron benefits from an ultra-lean operating model, with the majority of cash outlays being applied directly to R&D Share Price (AU$) Corporate Fundamentals (as at 30 June 2026) Market Capitalisation: AU$ 4.6M Primary Listing: ASX: PER Secondary Quotations: OTC: PERCF Shares on Issue: 1,522 Million Key Shareholders Mutual Investments Limited 5.4% Directors and Management 5.6% Financial Position (as at 30 June 2026) Cash Balance: AU$ 4.05 million Runway (per Appendix 4C): 3.9 quarters AS AT 30 JUN 2026 0 10 20 30 40 50 60 70 80 90 100 $- $0.001 $0.002 $0.003 $0.004 $0.005 $0.006 $0.007 $0.008 $0.009 $0.010 31-Dec-25 31-Mar-26 30-Jun-26 Millions Volume Asset Economics Acquisition Cost ~$4.5 Million (includes manufacture of one batch of drug substance) Confidential, substantially back-ended participation for licensor in success of product 11 CY2026 Presentation of data at scientific conferences 1H CY2026 ✓ Grant of provisional international nonproprietary name (INN) for HMBD-002 by WHO 1H CY2026 ✓ Completion of drug substance manufacture for new clinical trials 1H CY2026 ✓ Engagement with Vanderbilt Health to execute clinical trial in AML 2H CY2026 ✓ Release of completed HMBD-002 drug product for use in clinical trials 2H CY2026 Commencement of new CEO 2H CY2026 FDA approval of Vanderbilt AML study 2H CY2026 First patient in to Vanderbilt AML study 2H CY2026 Potential further clinical trial(s) in additional patient populations 2H CY2026 CY2027 Initial data from AML study CY2027 Percheron is focused on moving its pipeline forward expeditiously, with potential for rich, value-generating news flow over FY2026 PRELIMINARY Note: All timelines are indicative and subject to ongoing review info@PercheronTx.com www.PercheronTx.com