Interim analysis
We performed a predetermined interim analysis as per protocol. From the clinical trial protocol, two interim analyses based on the alpha spending approach of Lan and DeMets could be performed. One would be performed whenever 35 patients had passed away. If both the observed HR was less than or equal to 0.55 and its related p-value was less than 0.0167, the trial may be stopped for efficacy at this point. If the trial continued, the second interim analysis would take place after 70 people had expired. If the observed HR was less than or equal to 0.55 and its corresponding p-value was lower than or equal to 0.0218, the trial could be stopped for efficacy at this point.