On Monday, the New England Journal of Medicine published the results of a new treatment for a specific form of cancer. In that trial, all 12 patients that completed treatment with the new drug, called dostarlimab, had what was called a “100% response.” That is, every one of these patients saw their tumors completely eradicated.
Drug trails, especially early trials, often give murky results. Potential new treatments are given to very small numbers of patients, with little understanding of proper dosages, best duration of treatment, or potential side effects. The results are often overhyped in the media, which has a tendency to turn limited success into major triumphs, and very specific advances into general solutions.
So here’s a look at why these results are both terrific when it comes to validating the approach to certain forms of cancer, but also not the “cure for cancer” that many broadcast outlets seem to be touting.
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Any time the media seizes on a study this small, expect to be disappointed. In this case, the problem doesn’t lie with anything in the design of the trial, or the article reporting the results. It’s more in the way that media reports are trying to turn a specific solution into something like a general miracle.
Dostarlimab is a miracle. For those who would benefit from its treatment, it looks very likely to save them from a general course of chemo, radiation, and often debilitating surgery. It’s a complete game-changer that will radically improve lives. It’s just that the group who will benefit from this drug is a very small subset of the class “people with cancer.”
This treatment is one of a group of drugs known as immune checkpoint inhibitors. As with many potential cancer treatments, these drugs work to engage the body’s own immune system in taking out cancer cells. In this case, they do so by blocking the response of immune system cells which are drawn to the tumors, but which are then confused by a group of proteins on the surface of tumor cells. Those proteins essentially perform an old Jedi mind trick on the immune system’s T-cells, convincing them to “move along, these are not the bad cells you’re after.” Dostarlimab blocks that trick.
Without the cover of those T-cell sidelining proteins, the immune system correctly identifies the tumor cells as bad guys. It then engages the full immune system response to essentially consume them and clean up the residue. The tumors literally go away.
It’s a great treatment—in some ways, about the best you can hope for—though such drugs can have side effects, especially side effects that mimic some of the many autoimmune diseases, where the immune system turns against the body. However, the scale of the side effects and the duration of treatment make this an excellent option.
That’s why there are already immune checkpoint inhibitors in use for breast cancer, colon cancer, lymphoma, and many other forms of cancer. These are drugs that are helpful for many, though their effectiveness and success rate are rarely as wondrous as those in the dostarlimab trial.
Which finally brings it down to this: The people in the trial had a very specific form of rectal cancer known as mismatch repair–deficient, locally advanced rectal cancer. In another study, on chemo and radiation treatment, about 7.8% of rectal cancer patients had this form of the disease. It’s an absolutely awful form of rectal cancer whose general treatment usually involves not just the radiation and a prolonged course of chemo, but “surgical resection of the rectum.”
For people facing that diagnosis, dostarlimab looks like it is going to be not just an absolute game-changer—a drug that allows them to go on with their lives without the ravages of chemo, the risks and illness that come with radiation treatment, or the life-altering results of that surgery—and just … be cured. That’s not a bad day’s work. If these results hold up in larger trials, it’s going to be amazing.
Each year in the United States, there are over 40,000 new cases of rectal cancer. If results hold up, somewhere between 2,000 and 5,000 of those people can expect to benefit from dostarlimab. Everyone involved should take a bow.
And the media should stop promoting these results as if they’re a general cure for cancer.