14 Jun HAVE DOCTORS FOUND THE CURE TO CANCER?
Thousands of people across the world are diagnosed each day with the most dreaded disease: cancer. And despite the illness still killing massive numbers of people each year, many are becoming hopeful that a cure could be just around the corner.
Of course, curing the disease is simpler than it might sound. There are over 200 types of cancers, and each one is essentially a different illness than the others.
Still, with a massive amount of global brainpower devoted to decoding the mystifying disease, there are some signs that we are tantalizingly close to a cure for it – at least in some form.
A small clinical trial conducted by Memorial Sloan Kettering Cancer Center found that every single rectal cancer patient who received an experimental immunotherapy treatment had their cancer go into remission.
The trial began in late 2019, took 18 early-stage rectal cancer patients with the same tumor mutation who had no prior treatment and gave them the drug dostarlimab every three weeks for six months. Tumors completely disappeared in all 14 patients who had completed the treatment by the time the study was published (four more remain on track with similar results), and none have required follow-up treatment.
The results mark the first time immunotherapy alone eliminated the need for chemotherapy, radiation or surgery, which can cure patients but leave them with life-altering effects like infertility, bowel and relations dysfunction or permanent reliance on a colostomy bag.
After the course of treatment, cancer was undetectable on physical exam, endoscopy, PET, and MRI scans for every person, the researchers from MSKCC said in a presentation at the annual meeting of the American Society of Clinical Oncology this past Sunday.
One participant, Sascha Roth, was preparing to travel to Manhattan for weeks of radiation therapy when the results came in, Memorial Sloan Kettering said. That’s when doctors gave her the good news: She was now cancer-free.
“I told my family,” Roth told The New York Times. “They didn’t believe me.”
These same remarkable results would be seen in 14 patients to date. The study was published Sunday in the New England Journal of Medicine. All of the patients had rectal cancer in a locally advanced stage, with a rare mutation called mismatch repair deficiency (MMRd).
They were given six months of treatment with an immunotherapy drug called dostarlimab, from the pharmaceutical company GlaxoSmithKline, which helped fund the research. The cancer vanished in every single one of them.
Four people who were successfully treated for rectal cancer in a clinical trial at Memorial Sloan Kettering join the trial’s two main investigators.
The drug costs about $11,000 per dose, The Times reports. It was administered to each patient every three weeks for six months, and it works by exposing cancer cells so the immune system can identify and destroy them.
“This new treatment is a type of immunotherapy, a treatment that blocks the ‘don’t eat me’ signal on cancer cells enabling the immune system to eliminate them,” CBS News medical contributor Dr. David Agus explains.
“The treatment targets a subtype of rectal cancer that has the DNA repair system not working. When this system isn’t working there are more errors in proteins and the immune system recognizes these and kills the cancer cells.”
After six months or more of follow-up, the patients continued to show no signs of cancer — without the need for the standard treatments of surgery, radiation and chemotherapy — and the cancer has not returned in any of the patients, who have now been cancer-free for a range of six to 25 months after the trial ended.
“Amazing to have every patient in a clinical trial respond to a drug, almost unheard of,” Agus said, adding that it “speaks to the role of personalized medicine — that is identifying a subtype of cancer for a particular treatment, rather than treating all cancers the same.”
Another surprise from the study was that none of the patients suffered serious side effects.
“Surgery and radiation have permanent effects on fertility, health, bowel and bladder function,” Dr. Andrea Cercek, a medical oncologist and principal investigator in the study, said in an MSK news release. “The implications for quality of life are substantial, especially in those where standard treatment would impact childbearing potential. As the incidence of rectal cancer is rising in young adults, this approach can have a major impact.”
“It’s incredibly rewarding,” Cercek said, “to get these happy tears and happy emails from the patients in this study who finish treatment and realize, ‘Oh my G-d, I get to keep all my normal body functions that I feared I might lose to radiation or surgery.’”
Researchers agree the trial needs to now be replicated in a much bigger study, and noted that the small study focused only on patients who had a rare genetic signature in their tumors. But they say that seeing complete remission in 100% of patients tested is a very promising early signal.
Dr. Alan P. Venook, a colorectal cancer specialist at the University of California, San Francisco, who was not involved with the study, told the New York Times that complete remission in every single patient was “unheard-of”.
Dr. Hanna K. Sanoff of the University of North Carolina’s Lineberger Comprehensive Cancer Center, who was not involved in the study, said it is not yet clear if the patients are cured.
“Very little is known about the duration of time needed to find out whether a clinical complete response to dostarlimab equates to cure,” Dr. Sanoff wrote in an editorial accompanying the paper.
But she noted, “These results are cause for great optimism.”
The trial is expected to include about 30 patients, which will give a fuller picture of how safe and effective dostarlimab is in this group.
“While longer follow-up is needed to assess response duration, this is practice-changing for patients with MMRd locally advanced rectal cancer,” said study co-leader Dr. Luis Diaz Jr., head of the division of solid tumor oncology at MSK.
The American Cancer Society estimates that in 2022, there will be 44,850 new cases of rectal cancer.
Colorectal cancer is the second most common cause of cancer deaths in the U.S., according to the organization.
This year, colorectal cancer is expected to cause 52,580 deaths, the American Cancer Society estimates.
The clinical trial is continuing to enroll patients with MMRd rectal cancer tumors, the Memorial Sloan Kettering press release said.
Dostarlimab works by helping the immune system identify and destroy cancer cells. The drug, which is branded as Jemperli, is already used for patients with endometrial cancer, but it wasn’t clear if it would work for rectal malignancies. The participants in the trial had a type of rectal cancer called “mismatch repair deficiency”. About 5 to 10% of people with rectal cancer have this type of cancer, where the genes responsible for correcting any mistakes during cell replication are faulty. The study can’t tell us if dostarlimab will work in patients with other types of rectal cancer.
The cancer center is also looking into how dostarlimab might be able to help patients with other kinds of cancer that have MMRd tumors as well, such as stomach, prostate and pancreatic cancer.