Stupp, who has worked on the device for several years, acknowledged that it has prompted considerable skepticism from some experts in the field. Although the new data have not yet been peer-reviewed, he said he believes the results “firmly establish the survival benefit.”
The study, presented
at the annual meeting of the American Association for Cancer Research in Washington, involved 695 adult patients who were enrolled between July 2009 and November 2014. It found that the median survival for patients who were randomly assigned to use the device while getting the chemo drug temozolomide lived a median of 21 months compared with 16 months for those assigned to receive chemo without the device.
“I think this is fascinating, but the improvement is still quite modest,” said George Demetri, an oncologist at the Dana-Farber Cancer Institute who was on the AACR committee that accepted and highlighted the abstract. Exploring non-drug therapies is important given that glioblastoma patients survive, on average, less than 15 months following their diagnosis. “I'm in favor of any incremental benefit” for such a lethal disease, Demetri said.
Some critics — and even some supporters — have said Stupp should have designed the trial so that one group of patients would have gotten a placebo in the form of a device without any electrical current. Doing so, they noted, would have ensured that the reported benefit was valid. Stupp counters that such a sham device would have been impractical since patients would have known the difference because of the warming sensation the actual treatment causes on the scalp.
Two prominent brain-cancer specialists declined to discuss the study, signaling that they remain dubious.
The technology, called Optune, is manufactured by Novocure Inc. Interim results for the first 315 patients enrolled in the study, which were published in 2015 in JAMA, prompted an independent data and safety monitoring committee to recommend that the trial be ended early so that all patients could get the device if they wanted. The latest data show that the two-year survival rate for the full group of patients was 43 percent for those using the device while getting temozolomide, compared with 31 percent for those only receiving chemo. The five-year rate was 13 percent vs. 5 percent.
Optune has several components. The device has a generator that can be plugged into an electrical outlet or powered by a battery. It produces an electrical field that is conveyed via wires to four adhesive patches taped in place on a patient's shaved scalp. Each patch has an array of nine electrode discs. The electrical field being delivered changes direction rapidly, which Stupp speculates disrupts
the rapidly dividing cancer cells but does not affect healthy cells.
The device was initially approved by the Food and Drug Administration in 2011 to treat patients with glioblastoma that had returned after chemotherapy. In 2015, the agency approved the treatment for newly diagnosed patients who also were getting temozolomide, based on the interim data of the second trial. At the time, the FDA noted that the treatment wasn't a cure but seemed to increase survival by several months.
Researchers still aren't exactly sure how the device works. “It was a controversial approach,” said Patrick Wen, director of the Center for Neuro-Oncology at the Dana-Farber Cancer Institute, who has not been involved in the trial. But he predicted that skepticism will begin to wane given the new “positive” data. Tumor-treating fields now are in early-stage testing for ovarian and pancreatic cancers.
Jessica Morris of Brooklyn was diagnosed with glioblastoma a year ago after having a seizure while hiking with friends. The 53-year-old public relations executive, who has gone through surgery, radiation, chemotherapy and immunotherapy, began using Optune in May. Its manufacturer recommends that it be worn at least 18 hours a day. Morris typically adds on several hours.
Morris said she replaces the patches and shaves her head a few times a week. Because those arrays “look a bit weird,” she wears a scarf. She said she has had no effects other than feeling her head get a bit warm from the electrical fields. She hopes to extend her remission as long as possible and then look for an appropriate clinical trial.
Trial investigator Andrew Lassman, the chief of neuro-oncology at Columbia University, first heard about the device some years ago. He remembers thinking, “What is this thing, is it a joke?” Now he believes the approach is here to stay — “I don’t think it’s sci-fi,” he said — and calls the results “pretty good” even though the improvements are “incremental, not curative.”
He said that only 5 percent to 10 percent of his patients have opted to use the device. One reason is that it's impossible to hide: “For some patients, they’ll say, 'I’m proud to display that I'm fighting this cancer.' But others say, 'I don’t want anyone to know my business, I'd prefer to get an IV or a pill and be private.'”
At $21,000 a month, it's also costly. Standard Medicare doesn't cover it, and some other insurers are balking, as well. Novocure's vice president for financial and investor relations, Ashley Cordova, said the company has financial assistance programs in an effort to ensure that everyone prescribed the device can get it.