Is Precision Medicine the Next Great Frontier?
Genomic-based precision medicine isn’t just a lofty concept. Some patients are already being helped — just as some folks who spend hard-earned wages on lottery tickets are becoming instantly wealthy. Unfortunately, in both cases, the percentage of lucky ones isn’t high enough to warrant a lot of optimism.
The problem, say some experts, is that reality doesn’t jibe with the message being subtly — and not-so-subtly — conveyed by genetic-testing companies that market tests for cancer mutations, such as Caris Life Sciences and Foundation Medicine, and by hospitals who, hoping to capitalize on their precision-medicine programs, tend to focus heavily on their success stories and brush aside their failures.
Yes, there have been successes, and yes, progress is being made, but as outspoken oncologist Vinay Prasad of Oregon Health & Science University points out, as recently as last year, only about 15% of more than 600,000 U.S. patients with metastatic cancer were eligible for FDA-approved, genome-guided drugs. And since the drugs don’t work for everybody, fewer than half of those will actually benefit. It gets worse. Many who do benefit, he says, will relapse after a couple of years.
So, how long will it take to reach the point when all cancer patients can be helped? At the current rate of new FDA drug approvals, more than 200 years, says Dr. Prasad.
Slow, but steady?
Granted, even slow progress is progress. And precision-medicine advocates are quick to trumpet their successes, such as the recent FDA approval of a drug called larotrectinib, noteworthy because it’s the first drug to be approved based on tumor type, rather than location in the body.
“This distinction marks a new chapter for precision medicine,” says oncologist David Hyman, of New York’s Memorial Sloan Kettering Cancer Center. “While the concept of targeted therapy seemed wildly futuristic just two decades ago, we’ve seen firsthand — through a combination of advances in basic science, clinical practice, and genetic sequencing and an evolving design of clinical trials — how this treatment approach can benefit select individuals.”
Select individuals may indeed benefit. What worries the skeptics is that far more individuals will have their hopes raised and then dashed by misleading characterizations.
A recent article in healthnewsreview.org describes the ordeal that patients with incurable forms of cancer may face when they and their family members buy into the notion — subtly suggested by advertisements — that certain drugs will not only provide more time, but also improve the quality of their lives. “A treatment option for patients determined to keep fighting,” reads one such ad.
What the ad doesn’t say is that survival benefits seen in controlled trials of the drug in question are generally only a month or two, and that the side effects include feeling as if one has the flu, serious bleeding, high blood pressure, diarrhea, mouth ulcers, swelling of extremities, and a host of other issues, including an increased risk for blood clots, heart attack and stroke.
In another article, Kaiser Health News describes the ordeal of a 55-year-old woman, MaryAnne DiCanto, and her husband, Scott Primiano, whose hopes were bolstered by the promise of precision medicine, then crushed by one failed attempt after another. She died of breast cancer at 59.
There’s something about the term precision medicine. “You think it’s going to be more precise, like a laser versus a shotgun,” says Scott Primiano. “But it’s still a shotgun.”
Face to face with reality
“The most difficult thing is that things move too slowly,” acknowledges Dr. Nikhil Wagle, a cancer specialist at Boston’s Dana-Farber Cancer Institute, who helped develop precision-medicine tests. “You want to make a difference for every person you meet. However, even the most cutting-edge and recent findings may only help some people and not necessarily the person you are meeting with right now.”
Dr. Wagle is more optimistic than some, but understandably reluctant to make predictions. “It’s hard to put an exact timeline on it, but over the next decade, we will continue to get better and better treatment,” he says. “The strategies in precision medicine and looking at the combination of DNA, RNA, proteins, and the immune system – all of that together – as well as combinations of targeted therapies and immunotherapies done in a rational, sophisticated way – that’s where we will see progress.”
Scott Primiano, whose wife couldn’t be helped, has a more down-to-earth perspective. “Let’s not pretend this is something it isn’t,” he says. “I’m not saying we shouldn’t try it. I just don’t want people to have false hope.”