The control group had a 20% better survival rate than anticipated.

The question is, did they do something different (like monitor them and adjust their dosages of other stuff better) or was this good luck for that particular batch of patients, bad luck for CLSN? Or did CLSN err in initially computing expected survival?

The big mistake that CLSN made was being so confident in the results that they went with a 12 month study instead of a longer one. They said as much in the call, that there was some evidence that it reduce metastasis but the study was not long enough to tell.