"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.
Dr. Ram also presented evidence to suggest that NovoTTF therapy may have benefits in other forms of cancer. A study reported by his colleagues earlier this year at the European Society for Medical Oncology Congress in Milan showed that NovoTTF therapy (combined with chemotherapy) resulted in significant prolongation of survival in patients with NSCLC, compared with historical controls, he said.
"If this kind of therapy acts against brain cancer cells, it should act also against other tumor types," he reasoned.
In the study, which included 42 NSCLC patients, NovoTTF was delivered with newly designed electrodes placed on the chest and neck of patients with locally advanced, metastatic, stage IIIb and IV disease, he explained. The combination of NovoTTF and pemetrexed increased overall survival to 13.8 months, compared with 8.3 months seen with pemetrexed alone; the 1-year survival rate for the combination was 57%, compared with 30% reported for pemetrexed alone.
"We’re talking about something that appears to be acting against cancer cells regardless of origin," Dr. Ram said. "Action in the lung seems similar to what has been seen in GBM over time: a slow resolution of malignant pleural effusion and masses within the chest."
"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 study 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. "I was really surprised to see what happened in the lung cancer. I am a medical oncologist and I have never seen that complete a response. It’s surprising. We have to wonder if all that we know about the treatment of tumors is correct."
Dr. Ram acknowledged that per-protocol analysis of the findings 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 that we were traditionally using."
Dr. Ram disclosed that he is a consultant for NovoCure. Dr. Brandes did not disclose if she had any conflicts of interest at the meeting and did not respond to inquiries about disclosures.