Announcement PDF ONCOSIL MEDICAL LIMITED ABN 89 113 824 141 ASX | OSL Level 5, 7 Eden Park Drive, Macquarie Park, NSW 2113 AUSTRALIA TELEPHONE +61 2 8935 9629 WEB www.oncosil.com 1 ASX Announcement 27 October 2026 OncoSil™ Study Reports 100% Local Disease Control and Promising Surgical Outcomes in Locally Advanced Pancreatic Cancer Key highlights • Peer-reviewed clinical study published in the international oncology journal Cancers, reporting early outcomes in 17 patients with unresectable locally advanced pancreatic cancer (LAPC) treated with OncoSil™ in combination with gemcitabine plus nab-paclitaxel chemotherapy. • 100% local disease control at approximately 16 weeks comprising a partial tumour response in 43.8% of patients and stable disease in 56.2%. • 23.5% of patients underwent surgical resection following treatment, with four patients achieving R0 (clear-margin) resections. • Estimated median overall survival was 20.0 months from treatment initiation and 18.8 months from OncoSil™ implantation. • 100% technical implantation success with no implantation-related complications reported. Adverse events were predominantly mild to moderate in nature. Sydney, Australia – 27 October 2026: OncoSil Medical Limited (ASX: OSL) (“OncoSil Medical” or “the Company”), a medical device company focused on localised treatments for patients with unresectable locally advanced pancreatic cancer (LAPC) and distal cholangiocarcinoma (dCCA), is pleased to announce the publication of a new peer-reviewed clinical study in the Cancers journal, reporting preliminary clinical outcomes in patients treated with OncoSil™ in addition to systemic chemotherapy. The study is titled “Early Local Tumour Control and Feasibility of Intratumoral P-32 Microparticle Implantation in Patients with Locally Advanced Pancreatic Cancer: A Prospective Single-Center Observational Cohort Study” (Kontos A, et al. Cancers 2026;18:3331; published 15 October 2026; DOI: 10.3390/cancers18203331). Published Clinical Study Results The prospective, single-centre observational study was conducted at Agios Savvas Hospital in Athens, Greece, and included 17 consecutive, highly selected patients with unresectable locally advanced pancreatic cancer treated with OncoSil™ in addition to gemcitabine plus nab-paclitaxel chemotherapy. The study evaluated technical feasibility, preliminary safety, local disease control, tumour response, subsequent surgical resection and exploratory survival outcomes. ONCOSIL MEDICAL LIMITED ABN 89 113 824 141 ASX | OSL Level 5, 7 Eden Park Drive, Macquarie Park, NSW 2113 AUSTRALIA TELEPHONE +61 2 8935 9629 WEB www.oncosil.com 2 Key clinical results included: • 100% local disease control (16/16) at approximately 16 weeks among evaluable patients, comprising 43.8% (one subject underwent surgery before the 16-week time point); (7/16) achieving a partial response and 56.2% (9/16) demonstrating stable disease. Local disease control was 94.1% (16/17) across all treated patients. • 23.5% surgical resection rate (4/17), with all four patients achieving R0 (clear-margin) resections following treatment. • 81.2% of evaluable patients (13/16) achieved a CA19-9 tumour marker reduction of at least 50%, with a median reduction of 73.7% at 16 weeks. • 21.4% median reduction in tumour diameter at approximately 16 weeks. • 100% technical implantation success (17/17), with no implantation-related procedural complications reported. • Predominantly Grade 1–2 adverse events, with one Grade 3 abdominal pain event and no Grade 4–5 adverse events recorded. • Median local progression-free survival of 11.0 months and estimated median overall survival of 20.0 months, measured from chemotherapy initiation (9.7 months and 18.8 months, respectively, when measured from OncoSil™ implantation). With only three deaths during a median overall survival follow-up of 15.6 months, survival estimates remain exploratory and statistically immature. The publication adds to the growing body of clinical evidence investigating the addition of the OncoSil™ device to a multidisciplinary treatment approach for patients with unresectable locally advanced pancreatic cancer. Nigel Lange, CEO & Managing Director of OncoSil Medical, said: “The publication of this peer-reviewed clinical study adds to the growing body of clinical evidence evaluating OncoSil™ in patients with unresectable locally advanced pancreatic cancer. The reported 100% local disease control among evaluable patients at approximately 16 weeks, together with four patients subsequently achieving R0 surgical resection, are encouraging findings in a patient population with significant unmet medical need. The successful implantation of OncoSil™ in all 17 patients, with no implantation-related procedural complications reported, also supports the technical feasibility of the treatment approach in this study. While these results are from a small patient cohort, they provide further clinical experience on the use of OncoSil™ in addition to chemotherapy as part of a multidisciplinary treatment approach for locally advanced pancreatic cancer. We remain focused on advancing the clinical development of OncoSil™ and building the evidence base for targeted phosphorus-32 (P-32) microparticle therapy, with the aim of expanding treatment options for patients with this challenging disease.” ONCOSIL MEDICAL LIMITED ABN 89 113 824 141 ASX | OSL Level 5, 7 Eden Park Drive, Macquarie Park, NSW 2113 AUSTRALIA TELEPHONE +61 2 8935 9629 WEB www.oncosil.com 3 Click here to read the full publication. Click here to view this announcement on Investor Hub. Authorisation & Additional Information This announcement was authorised by the Board of Directors of OncoSil Medical Limited. For further information, please contact: About OncoSil Medical OncoSil Medical (ASX) is a global medical device company focused on Interventional Oncology, with a mission to improve outcomes for people living with cancer. The company has developed OncoSil™, a single-use brachytherapy (internal radiation) device that delivers a pre-determined dose of beta radiation directly into cancerous tissue using targeted intratumoural placement of Phosphorous-32 (³²P) Microparticles. Its targeted approach enables a greater radiation dose to be delivered directly to the tumour while limiting exposure to surrounding critical organs. In the United States, OncoSil™ is indicated for the treatment of patients with distal cholangiocarcinoma (dCCA) that is both unresectable (locally advanced and/or unfit for surgery) and non-metastatic, as an adjunct to systemic therapy. In markets outside the United States where OncoSil™ has received regulatory approval, OncoSil™ is indicated for the treatment of patients with unresectable locally advanced pancreatic cancer, in addition to gemcitabine-based chemotherapy. Pancreatic cancer is the 12th most common cancer in men and the 11th most common cancer in women across the globe, with 500,000 new cases detected every year1. Since pancreatic cancer is generally diagnosed at a later stage, it has a poor prognosis for long-term survival. Distal cholangiocarcinoma (dCCA) is a rare form of bile duct cancer. It is often diagnosed at an advanced stage, when surgical treatment may no longer be possible, and is associated with a poor prognosis. OncoSil™ has received CE Marking approval, providing marketing authorisation in the European Union and the United Kingdom. OncoSil™ has also received approval from the U.S. Food and Drug Administration (FDA) under a Humanitarian Device Exemption (HDE) for the treatment of patients with unresectable, non-metastatic distal cholangiocarcinoma (dCCA), as an adjunct to systemic therapy. OncoSil™ has been designated as a Breakthrough Device in Europe and the United States. It is currently approved for sale in 30+ countries, including the European Union, United Kingdom, United States, Australia, Saudi Arabia, Türkiye and Israel, with commercial treatments using the device already undertaken in Spain, Italy, Austria, Germany, Greece, Türkiye, Portugal, Israel and the UK. To learn more, please visit: www.oncosil.com/ 1 https://gco.iarc.fr/en Mr. Nigel Lange CEO & Managing Director E: nigel.lange@oncosil.com T: +49 160 9642 4981 Mr. Tim Luscombe & Ms. Nova Taylor Joint Company Secretaries E: tim.luscombe@bio101.com & nova.taylor@bio101.com T: +61 429 707 079 & +61 414 877 703