This is an exploratory, randomized, double-blind, multicentre, placebo-controlled study of RTP-026.

The study population will consist of men and women with documented evidence of ST-elevation myocardial infarction (STEMI) referred to primary Percutaneous Coronary Intervention (PCI).

An exploratory, randomized, double-blind, multicentre, placebo-controlled study of RTP-026 to assess safety, tolerability, and efficacy in patients with (STEMI).

The study population is men between 18-85 years and post-menopausal women up to 85 years with documented evidence of STEMI referred to primary PCI with acute onset of chest pain lasting <12 hours and neutrophil to lymphocyte ratio (NLR) in the range of 3-17 at hospital admission (Please refer to inclusion criteria).

The participants will be given three 30-minute intravenous infusions of RTP-026 or placebo (the investigational product). The first dose is to be initiated within 2 hours following the establishment of reflow after PCI, and the following two study treatments with 8-hour intervals.

The purpose of this study is to evaluate the safety, tolerability and efficacy of RTP-026 versus placebo in multiple doses.

Inclusion Criteria:

• Informed consent for participation in the study has been obtained prior to initiating any study-specific procedures
• Men between 18-85 years of age and post-menopausal women up to 85 years of age
• Acute onset of chest pain of < 12 hours duration
• STEMI as characterized on ECG by 2 mm ST elevation in 2 or more V1 through V4 leads or presumed new left bundle branch block with a minimum of 1 mm concordant ST elevation or 1 mV ST elevation in the limb lead (II, III and aVF, I, aVL) and V4-V6 or ST depression in 2 or more V1 through V4 leads indicating posterior acute myocardial infarction (AMI)
• Eligible for primary PCI
• NLR in the range of 7-17 at hospital admission. In patients with chest pain lasting > 3 - ≤ 6 hours at admission, the NLR should be in the range of 4.8-17 and for patients with chest pain lasting ≤ 3 hours at admission, the NLR should be in the range of 4.8-17, or the neutrophile count should be ≥ 9 x 10E9/L, irrespective of the lymphocyte count. For STEMI patients with an anterior or anterolateral infarction, the NLR should be ≥3.

Exclusion Criteria:

• Participation in any other study involving investigational drug(s) during the study and within 4 weeks prior to study entry
• Previous exposure to RTP-026
• Time from symptoms onset to primary PCI > 12 hours
• Previous CABG
• Evidence of active malignant disease
• Ongoing treatment with immune suppressive compounds
• Any condition that, in the view of the investigator, would suggest that the patient is unable to comply with the study protocol and procedures
• Known contraindications to CMR
• ORBI Risk Score > 12