March 24, 2006

Antigenics has announced top-line results from its Phase III study of Oncophage (vitespen) in kidney cancer patients who are at high risk of recurrence after surgery. The analysis was triggered based on the number of events (defined as recurrence of disease or death of a patient prior to recurrence) reported by study investigators. However, an independent review by the trial's clinical events committee (CEC) revealed that a substantially smaller number of events had actually occurred. The analysis showed a trend in favor of Oncophage for recurrence-free survival (the study's primary endpoint), and a trend against Oncophage for overall survival (secondary endpoint); both findings were not statistically significant.

The results of the CEC review revealed that the required number of events to conduct analysis of the recurrence-free survival endpoint was not met. The analysis of the overall survival endpoint is considered an interim assessment. At this time, it is unclear as to why opposing trends were observed between recurrence-free survival and overall survival.