“We do this to all our patients. We intoxicate them,” Dr. Ram said. “So even if NovoTTF did not extend survival, if it was equivalent to chemotherapy [for survival], it may still improve quality of life.”
Dr. Ram did not know the median length of time that the NovoTTF cohort wore the device, but an earlier phase II study followed some patients up to 59 months. He noted that “70% are still alive; that's unheard of.”
“There were concerns that patients might have more headaches or seizures, but there were none,” he added.
In the current study, the rate of adverse events related to the central nervous system was similar (66% for NovoTTF and 67% for chemotherapy). Seizures occurred in 15% of the NovoTTF group and 12% of the chemotherapy group, and headaches occurred in 18% and 13%, respectively.
“It's very interesting and exciting, even if we do not yet have enough definitive data,” commented Dr. Alba B. Brandes, moderator of the session and the chair of medical oncology at Azienda USL, a group of nine hospitals in and around Bologna, Italy.
The investigators have been criticized for repackaging their nonsignificant intent-to-treat results into per-protocol results that show significance, she said. “An intention-to-treat population and per-protocol population are two different things, and from a statistical point of view, it is sometimes difficult for the oncologic community to accept.” Despite those reservations, she said that the per-protocol observations should not be dismissed, because when they are analyzed in this way the results are highly significant.
Dr. Ram acknowledged that per-protocol analysis is unconventional, but “there is no precedent for this kind of therapy and I think we may need to redesign the way we assess results in the future. We cannot use the same guidelines and definitions we were traditionally using.”