Some selections from this even longer article:
"To Gatenby's knowledge, no one had endeavored to exploit evolution against cancer in a clinical trial until he developed his prostate cancer experiment. He picked prostate cancer to test this approach partly because, unlike other cancers, a routine blood draw for a molecule called prostate-specific antigen (PSA) can offer an immediate proxy for the cancer’s progression.
To design a clinical trial, Gatenby and his Moffitt collaborators first needed to account for their idea that tumor cells vie against each other for resources. ...............................................The computer simulations they ran with these equations estimated how quickly drug-resistant cells would outcompete other tumor cells when exposed to the continuous dosage of Zytiga typically given to advanced-stage prostate cancer patients.......................
In the simulations, the typical administration of the drug led to drug-resistant cancer cells rapidly running rampant. The treatment would ultimately fail each time. That bleak outcome matched up with the results seen in hospital records. In contrast, the computer simulations suggested that if Zytiga were administered only when the tumor seemed to be growing, then the drug-resistant cells would take much longer to gain enough advantage to overrun the cancer..................................
In 2014 the Moffitt team managed to get the first small study to test this adaptive therapy approach off the ground, recruiting Robert Butler and a small group of other men with advanced prostate cancer. Butler’s oncologist explained to him how it would work. He would remain on the Lupron he’d taken for years, and each month he would go to the hospital to get his PSA level tested, to judge whether his prostate tumor was growing. Every three months, he would get a CT scan and a full-body bone scan to watch for disease spread. Whenever his PSA level edged above where it stood when he entered the trial, he would start taking the more powerful Zytiga. But when his PSA level fell to under half of the baseline, he could go without Zytiga. This is appealing because Zytiga and drugs like it can cause side effects like hot flashes, muscle pain, and hypertension.
The Moffitt approach also promised to be far cheaper than taking Zytiga continuously. When purchased wholesale, a one-month supply costs almost $11,000. Butler had health insurance, but even so, his first month’s supply each year would set him back $2,700 in out-of-pocket copayments, and $400 a month thereafter. Going off the drug whenever his PSA level was low would translate to huge cost savings.........................
Butler was participating in a so-called pilot trial, which was less rigorous than a large clinical trial, because it didn’t randomly assign patients to receive the experimental or standard treatments. Rather, the study relied on a group of patients treated outside the trial as well as results from a 2013 paper on Zytiga to come up with a benchmark for how patients typically fare when receiving continuous dosing of the drug.
When the early results of their new trial trickled in, the Moffitt scientists were gratified and relieved. Ahead of the trial, “we were, to be honest, terrified,” Gatenby says. The benefit of adaptive therapy appeared to be huge. Of the 11 men in the study, one left the trial after his disease spread, but most were living longer than expected without their cancer progressing. Men getting continuous dosing of Zytiga go a median of 16.5 months before the cancer becomes resistant to the drug and spreads. In comparison, the median time to progression for the men receiving adaptive therapy was at least 27 months. Moreover, they were on average using less than half of the standard amount of Zytiga. Joel Brown, an evolutionary ecologist and one of Gatenby's collaborators, said the team felt a moral obligation to get the word out: “The effect was so big that it would be unethical not to report it immediately,” he says.
They published a report in 2017, far earlier than anticipated, to a generally positive reaction from prostate experts—particularly because it suggested a way that people with cancer might live longer with less medication. “If you can reduce side effects, I think that’s fantastic,” says Peter Nelson, an oncologist who studies prostate cancer at the Fred Hutchinson Cancer Research Center in Seattle. “Conceptually it’s a beautifully simple approach.” Jason Somarelli, a biologist at the Duke Cancer Institute, calls Gatenby a pioneer: “He’s turning cancer into a chronic disease.”......
Late last year, Gatenby presented his work at a meeting of prostate cancer specialists. In the question and answer session afterward, an attendee shared his surprise at the results. “I guess what you’re saying is that we’ve been doing it wrong all these years,” the man mused, according to Gatenby. “I was literally speechless for a few moments,” Gatenby admits, “and then I said, ‘Well, yeah, I guess that’s what I’m saying.’” He is still dwelling on the exchange and wishes he could somehow find the man and apologize. He’s not taking back what he said; he does think the profession can do better. But, he says, “I should have been more diplomatic.”
Butler tells me about
a time when he and some of the Moffitt researchers brainstormed alternative slogans. “We finally came up with ‘Our aim is to make you die of something else’—which I thought was lovely,” he adds. “It’s more true.”"
https://www.wired.com/story/cancer-treatment-darwin-evolution/