Announcement PDF Racura Oncology Ltd • ABN 61 149 318 749 • L36 1 Macquarie Place Sydney NSW 2000 Australia T. +61 2 8051 3043 • E. info@racuraoncology.com • www.racuraoncology.com ASX Announcement Racura Oncology Receives Governance Approval for RC220 HARNESS-1 Lung Cancer Trial § Governance approval received from Monash Health for the HARNESS-1 Phase 1 trial of RC220 in EGFR non-small cell lung cancer patients being treated with osimertinib § Trial aims to address the significant unmet medical need of preventing or delaying resistance to standard of care EGFR-mutant tyrosine kinase inhibitors such as osimertinib § Four additional clinical trial sites expected to be activated on the trial in the coming months. 16 March 2026 – Racura Oncology Limited (“Racura”) is pleased to announce it has received governance approval from Monash Health for its Phase 1 clinical trial assessing the safety, tolerability and pharmacokinetics (PK) of RC220 (E,E-bisantrene) in combination with osimertinib (Tagrisso® ; AstraZeneca), in patients with non-small cell lung cancer (NSCLC) who have activating epidermal growth factor receptor mutations (EGFRm). Human ethics approval for this trial was received in November 2025 (ASX Announcement: 26 November 2025). Racura Oncology Principal Scientist, Dr. Rodney Cusack commented: "With governance approval now secured, we are able to move forward with the clinical trial of RC220 in patients with EGFR-mutated NSCLC. This approval confirms that the necessary site infrastructure, resources and oversight are in place, allowing us to progress safely and efficiently. We remain focused on evaluating the potential of RC220 as an RNA and DNA G4 binder to target key pathways of osimertinib resistance. This important milestone brings us one step closer to making a meaningful impact for patients." Teams from Racura Oncology, Monash Health, and Contract Research Organisation (CRO) Beyond Drug Development are scheduled to meet at Monash Medical Centre (Clayton, Victoria) for site initiation and training on 23 March 2026 under the supervision of Principal Investigator Dr Surein Arulananda. Completion of this site training and subsequent site activation will enable the first patients to be recruited into the trial. HARNESS-1 Trial Overview The HARNESS-1 trial is a multi-centre, Phase 1a/b study, using circulating tumour DNA (ctDNA) to screen and enrol EGFRm NSCLC patients receiving treatment with osimertinib. The trial will commence with a ctDNA screening stage, followed by dose escalation of RC220, where between 12 and 40 patients will receive intravenous (IV) infusion of RC220 on Day 1 of a 21-day cycle in combination with standard of care maintenance osimertinib therapy. This treatment stage will begin by enrolling participants into single-patient cohorts under an accelerated trial design (ATD), intended to balance the need for careful safety evaluation with the objective of reaching clinically active dose levels as quickly as possible. Once the ATD stage is complete, participants will be enrolled into a Bayesian Optimal Interval (BOIN) dose escalation study, using larger patient cohorts to identify the maximum tolerated dose (MTD) of RC220. Participants in the trial will continue to be treated with RC220 and osimertinib until they reach any of the following outcomes: successful control of disease; one year of treatment; disease progression; unacceptable toxicity; or withdrawal of consent. Racura Oncology Ltd • ABN 61 149 318 749 • L36 1 Macquarie Place Sydney NSW 2000 Australia T. +61 2 8051 3043 • E. info@racuraoncology.com • www.racuraoncology.com Once the MTD of RC220 has been determined, all accumulated safety and PK data will be analysed before initiation of the double-blind, randomised dose expansion Phase 1b stage. In this stage, 40 participants will be randomised to one of two RC220 dose levels in combination with standard of care osimertinib. Patients will be monitored for safety and PK, together with a range of secondary and exploratory endpoints, including progression free survival (PFS), overall survival (OS), changes in levels of ctDNA, and changes in the cancer-specific mutations present in patients. -ENDS- Q&A Why is there such a wide range in the number of patients needed in the Phase 1a stage? It is impossible to know how many patients will be needed in the Phase 1a stage of this study as the aim is to identify the optimal dose of RC220 in combination with osimertinib. The Bayesian design used in this trial allows the clinicians to “home in” on the best dose of RC220, but to achieve this outcome they may need to treat more patients. Identifying the best dose early will provide greater probability of success in the dose expansion stage and future studies. This approach also helps satisfy the requirements of the US FDA’s Project Optimus which aims to better balance the efficacy and side effects of new cancer treatments. Where can I find out more about this lung cancer trial? Details of the HARNESS-1 trial, including open and recruiting sites, can be found on the Australian New Zealand Clinical Trial Registry (ACTRN12626000325303): https://anzctr.org.au/Trial/Registration/TrialReview.aspx?id=390394&isReview=true. Enquiries concerning participation in this trial can be directed via email to Racura Oncology at trials@racuraoncology.com. Racura Oncology Ltd • ABN 61 149 318 749 • L36 1 Macquarie Place Sydney NSW 2000 Australia T. +61 2 8051 3043 • E. info@racuraoncology.com • www.racuraoncology.com About Racura Oncology (ASX: RAC) Racura Oncology (ASX: RAC) is a Phase 3 stage clinical biopharmaceutical company with a dedicated mission to be at the heart of cancer care. Racura’s lead asset, (E,E)-bisantrene, is a small molecule anticancer agent that primarily functions via G4-DNA & RNA binding, leading to potent inhibition of the important cancer growth regulator MYC. (E,E)- bisantrene has demonstrated therapeutic activity in cancer patients with a well characterised safety profile. Recent discoveries made by Racura have enabled composition of matter IP filings that provide for 20 years of patent protection over (E,E)-bisantrene. Racura is advancing a proprietary formulation of (E,E)-bisantrene (RC220) to address the high unmet needs of patients across multiple oncology indications, with a Phase 3 clinical program in acute myeloid leukaemia (AML), a Phase 1a/b program in mutant epidermal growth factor receptor non-small cell lung cancer (EGFRm NSCLC), and a Phase 1a/b program in combination with the anthracycline doxorubicin, where we aim to deliver both cardioprotection and enhanced anticancer activity for solid tumour patients. Racura Oncology has collaborated with Astex, Emory University, MD Anderson, Sheba City of Health, UNC School of Medicine, University of Wollongong, and University of Newcastle. Racura is actively exploring partnerships, licence agreements, or a commercial merger and acquisition to accelerate access to RC220 for patients with cancer across the world. Learn more at www.racuraoncology.com. If you have any questions on this announcement, or any past Racura Oncology announcements please visit our Interactive Announcements page. Racura encourages all investors to go paperless by registering their details with the Company’s share registry, Automic Registry Services, at www.automicgroup.com.au. Release authorised by: Daniel Tillett, CEO info@racuraoncology.com Media contact: Cherie Hartley +61 418 737 020 cherie.hartley@irdepartment.com.au