There were no differences between treatment groups in the primary efficacy endpoint of infarct size measured by creatine kinase MB fraction area under the curve ( AUC ) ( median 5156 , 5043 , 4419 , and 5253 ng h/mL in the placebo , delcasertib 50 , 150 , and 450 mg/mL groups , respectively ) in the anterior STEMI cohort .