Immunomodulation of EA-230 Following On-pump Coronary Artery Bypass Grafting (CABG)

Systemic inflammation is a condition in which the innate immune system is activated due to a variety of causes such as sepsis, trauma, and major surgical interventions. The clinical condition in which the body responds to such stimuli by the release of circulating inflammatory mediators is well known as the systemic inflammatory response syndrome (SIRS) and is defined by tachypnoea, tachycardia, leucocytosis or leucopenia and hyper- or hypothermia.

Although this activation of the immune system is essential for survival, the often subsequent overwhelming pro-inflammatory response may be detrimental. Of the many downstream consequences of this exaggerated inflammatory response, organ injury and failure is the most serious, most often involving the kidneys. Multiple organ failure (MOF) is associated with high morbidity and mortality, whereas failure of kidneys is an independent prognostic factor for mortality in critically ill patients.

This exaggerated systemic pro-inflammation also occurs during major surgical procedures, especially in cardiac surgery procedures. Multiple stimuli during these procedures, such as sternotomy, extra-corporal cardio-pulmonary bypass (ECC) and aortal cross-clamping, account for substantial systemic inflammatory activation. The extent of inflammation following this procedures is directly associated with patient outcome, as high post-operative levels of IL-6 have been proven to correlate with adverse outcome and mortality. Also at organ level, the incidence of inflammation associated development of acute kidney injury (AKI) following cardiac surgery is high and correlates with adverse outcome and mortality.

To date, no immunomodulatory treatments, aimed at dampening the (acute) systemic inflammatory reaction following cardiac surgery with cardio-pulmonary bypass, have shown to improve essential outcome. Current strategies consist of prevention and supportive treatment; new strategies aiming at attenuating this exaggerated pro-inflammatory response are therefore warranted.

EA-230 is a novel pharmacological compound, developed for the treatment of systemic inflammation and associated organ dysfunction. It is a linear tetrapeptide derived from the human chorionic gonadotropin hormone (hCG). It has shown anti-inflammatory properties and protects against organ failure and associated mortality in several pre-clinical models of sepsis or systemic inflammation. As EA-230 attenuates the pro-inflammatory response in neutrophils and monocytes ex vivo, and neutrophil influx in tissues during systemic inflammation in vivo is abrogated, it is thought that EA-230 acts by protecting the host against the detrimental effects of neutrophils during acute systemic inflammatory diseases, thereby preventing organ damage.

A recently performed phase I study into the safety and tolerability of EA-230 in 24 subjects showed that continuous administration of EA-230 up to 90 mg/kg/hour infused intravenously is well tolerated and has an excellent safety profile. This profile was confirmed in a consequent executed phase IIa study in which 36 healthy subjects received the same dosages of EA-230 during human experimental endotoxemia. In this human model of controlled systemic inflammation elicited by the administration of a low dose of endotoxin, the anti-inflammatory effects of EA-230 shown in pre-clinical studies were confirmed and the optimal dose was established. Subjects treated with the highest dose (90 mg/kg/hour) showed less flu-like symptoms, development of fever was suppressed, and reduced levels of pro-inflammatory mediators (among others Interleukin-6 and Interleukin-8) were observed compared to placebo-treated subjects.

This current study is a combined phase IIa/IIb, randomized, placebo-controlled, double-blind, clinical trial. In the first part, phase IIa, the study aims to confirm safety and tolerability in a patient population (n=60, 30 active and 30 placebo) with systemic inflammation elicited by on-pump cardiac surgery. In the second part, phase IIb, the immunomodulatory effect of EA-230 is studied in a same patient population (n=180, 90 active and 90 placebo, including patients from part 1).

After inclusion of 90 patients, halfway the study, an additional adaptive power analysis will be performed to re-evaluate group size and power. Efficacy and sample size re-determination will be performed by the statistician of the Data Safety Management Board (DSMB).