RTP-026, A POTENTIAL FIRST-IN-CLASS CARDIOPROTECTANT, SHOWS STRONG SAFETY AND PROMISING EFFICACY SIGNALS IN A PHASE 2a STUDY IN PATIENTS WITH SEVERE HEART ATTACK

1 RTP-026, A POTENTIAL FIRST-IN-CLASS CARDIOPROTECTANT, SHOWS STRONG SAFETY AND PROMISING EFFICACY SIGNALS IN A PHASE 2a STUDY IN PATIENTS WITH SEVERE HEART ATTACK The clinical Phase 2a study included 66 patients with a severe form of ST-elevation myocardial infarction (STEMI) also referred to as heart attack, treated with acute percutaneous coronary intervention (PCI). Top-line results of the study identified RTP-026 as safe and well tolerated, with several parameters pointing towards positive treatment effect on post PCI infarct size and cardiac function. The study outcome provides further strong support for the continued development of RTP-026 into Phase 2b. CEO Anders Kronborg commented: “We are encouraged by the promising Phase 2a results for RTP-026. STEMI patients with a high inflammatory response remain at substantial risk of inflammation-driven cardiac injury despite successful PCI and revascularization. With an increasing elderly population worldwide, the indication represents a growing medical need. The efficacy signals observed in this study show that targeting the resolution of inflammation has potential as a new approach to cardio- protection in STEMI patients. Together with the strong safety and tolerability data, these findings provide solid support for taking RTP-026 into Phase 2b, which we expect to start by end 2026.” Copenhagen, Denmark – 14 September 2026 – ResoTher Pharma A/S, a biotechnology company developing a new class of resolution therapeutics for acute hyperinflammatory disorders, today announced encouraging top-line results from a Phase 2a clinical study of its lead drug candidate, RTP-026, in patients with acute myocardial infarction. RTP-026 is a novel Annexin A1 mimetic designed to promote resolution of excessive inflammation, generate tissue repair, and potentially protect organ function without general suppression of the immune system to provide better patient outcomes. The Phase 2a study was a randomized, double-blind and placebo-controlled clinical trial, enrolling 66 patients with a severe ST-elevation myocardial infarction (STEMI) undergoing standard treatment in the form of percutaneous coronary intervention (PCI). The study was designed to evaluate the safety and tolerability of ascending doses of RTP-026, as well as to explore potential efficacy signals. Inflammation plays a critical role in the response to myocardial infarction and for post PCI cardiac complications. Patients enrolled in the study had a high inflammatory drive, identifying a population considered to be at increased risk of inflammation-mediated cardiac tissue damage, cardiac dysfunction, heart failure and death following STEMI and PCI. Encouraging efficacy findings and strong safety results Patients in the Phase 2a study were randomized to RTP-026 (3:4) or placebo (1:4) in two ascending dose groups of 25 µg/kg and 75 µg/kg. Treatment was given as three (3) IV infusions within 24 hrs after PCI. There was an imbalance in disease severity at baseline with more patients in the two active arms having anterior infarcts (50%) than patients in the placebo arm (31.1%) before treatment. Particularly in the 75 µg/kg dose arm, both cardiac troponin T (cTnT) and CK-MB, two important biomarkers for myocardial injury, were considerably higher at baseline than in the placebo arm. Despite patients in the RTP-026 treatment arms being more severely ill at baseline than patients in the placebo arm, they had numerically lower cTnT scores than placebo and comparable CK-MB 24 hrs after PCI. At 24 hrs, cTnT scores had increased considerably more in the placebo arm compared to the two active arms; 615% (placebo), 129% (25 µg/kg), 65% (75 µg/kg). In terms of cardiac function, measured on cardiac MR as left ventricular ejection fraction (LVEF), both RTP-026 treatment arms 2 improved 3.2-fold more than placebo; from 46.0% to 54.0% in the 25 µg/kg dose arm and from 39.0% to 47.0% in the 75 µg/kg dose arm versus from 43.5% to 46% in the placebo arm. These data were further supported by numerically smaller final infarctions in the active arms. RTP-026 Phase 2a (STEMI): Topline results 25 µg/kg 75 µg/kg Placebo No of patients (Randomized) 24 26 16 Percentage with anterior infarct 50% 50% 31.3% Discontinuations (non-dose related) 3 patients 2 patients 2 patients cTnT at baseline/24 hrs (ng/L, median) 678 / 1,552 1,190 / 1,960 439 / 3,140 CK-MB at baseline/24 hrs (µg/L, median) 52.80 / 46.70 181.00 / 54.80 72.90 / 40.20 Improvement in median LVEF at day 90 vs day 1- 5 post PCI 8% (from 46% to 54% 8% (from 39% to 47%) 2,5% (from 43.5% to 46%) Infarction size measured at day 90 (gr, median) 6.6 8.7 9.3 RTP-026 was safe and well-tolerated in this high-risk STEMI population in doses up to 3x75 µg/kg with no fatal cases or rehospitalisations due to major adverse CV events, and no withdrawals due to adverse events. Serious treatment emergent adverse events were reported in 3 patients with active treatment (all evaluated by the clinician to be due to the underlying disease and not drug related) and in 1 patient with placebo treatment. Treatment emergent adverse events were well balanced across groups, and no new safety signal was identified. Because the Phase 2a study was designed primarily to establish the safety and tolerability profile of RTP-026 in this high-risk STEMI population and explore preliminary efficacy signals, it was not statistically powered to demonstrate significance of the results. Next steps for RTP-026 in STEMI Based on the encouraging safety, tolerability and preliminary efficacy findings from the Phase 2a study in STEMI patients, ResoTher Pharma has started preparations of an international clinical Phase 2b Proof-of-Concept study with RTP-026. Further details regarding the scope, design and time plan of the Phase 2b programme will be provided later in 2026. About RTP-026 RTP-026 is an investigational, first-in-class Annexin A1 mimetic designed to engage biological pathways involved in the natural resolution of inflammation. This represents a novel approach to the treatment of hyperinflammation for better organ protection rather than broadly suppressing the immune system. In several pre-clinical models of hyperinflammatory disorders, RTP-026 has shown potential to effectively reduce hyperinflammation-associated tissue damage, promote tissue repair and protect organ function. Currently, RTP-026 is in clinical development as a potential cadioprotective treatment for patients with an ST-elevation myocardial infarction (STEMI) undergoing Percutaneous Coronary Intervention (PCI). RTP-026 is currently investigational and has not been approved by any regulatory authority. About ResoTher Pharma ResoTher Pharma is a clinical stage biotechnology company focused on the development of a novel class of Annexin A1-based resolution therapeutics for better treatment of acute hyperinflammatory disorders. ResoTher Pharma’s activities center on a scientific invention from William Harvey Research Institute, Queen Mary University of London, UK, to which the company owns all rights. Lead drug candidate, RTP-026, is in clinical Phase 2 development as a potential cardioprotectant to reduce post-PCI inflammatory cardiac tissue damage and improve heart function for better patient outcomes Media Contact Mai Zeilund, Zeilund & Co., [email protected] / +45 71 900 523 Investor Contact CEO Anders Kronborg, [email protected] / +45 31 51 63 43 or CFO Hanne Vissing Leth, [email protected] / + 45 53 88 99 02

The release as fetched from its publisher. resotherpharma.com ↗