Cancer trial delivers ‘unheard-of’ result: complete remission for everyone

A small trial of a new cancer drug has reportedly provided a result never before seen — the total remission of cancer in all of its participants.

According to a report in the New England Journal of Medicine, a dozen rectal cancer patients saw their tumors disappear completely after they received an experimental drug called dostarlimab.

“I believe this is the first time this has happened in the history of cancer,” Dr. Luis Alberto Diaz Jr., one of the trial leaders and a medical oncologist at Memorial Sloan Kettering (MSK) Cancer Center, told The New York Times.

The 12 participants had a specific type of rectal cancer that tends to be resistant to radiation and chemotherapy treatments. Only about 5% to 10% of rectal cancer patients have the type of rectal cancer that was addressed in the study.

The trial participants received 500 milligrams of dostarlimab every three weeks for six months, according to the study.

It was at first believed that most of the patients would still need to undergo chemotherapy, radiation therapy and potentially surgery, the study’s authors said. But instead, all 12 patients’ cancers were completely cleared after only taking dostarlimab.

Researchers say the participants’ tumors were undetectable on physical exams, endoscopies, as well as PET and MRI scans.

It has been more than two years since the drug therapy was completed. and none of the patients required further treatment and none of their cancers have grown back, researchers said.

Dostarlimab belongs to a class of drugs called immune checkpoint inhibitors, according to Dr. Hanna Sanoff, an oncologist at the Lineberger Comprehensive Cancer Center at the University of North Carolina.

“And these are immunotherapy medicines that work not by directly attacking the cancer itself but actually getting a person’s immune system to essentially do the work,” Sanoff told NPR.

“And these are drugs that have been around in melanoma and other cancers for quite a while but really have not been part of the routine care of colorectal cancers until fairly recently.”

While the results have astonished some, others say it is important to remember that more research is needed, Sanoff said.

“These results are cause for great optimism,” but without further research, dostarlimab cannot yet replace the standard, curative treatment for mismatch repair-deficient rectal cancer, Sanoff wrote in a commentary of the new trial published in NEJM.