This new cancer drug has the potential to revolutionise the field

Every rectal cancer patient who got an experimental immunotherapy treatment went into remission, according to a small clinical trial conducted by Memorial Sloan Kettering Cancer Center.

When the results were announced, one of the participants, Sascha Roth, was ready to travel to Manhattan for weeks of radiation therapy, according to Memorial Sloan Kettering. That’s when her physicians informed her that she was cancer-free.

Roth told The New York Times, “I told my family.” “They didn’t believe me.”

To date, 14 patients have shown the same remarkable results. The research was published in the New England Journal of Medicine on Sunday. All of the patients had rectal cancer that had progressed locally and had an uncommon mutation known as mismatch repair deficiency (MMRd).

They were given a six-month course of treatment with dostarlimab, an immunotherapy drug developed by GlaxoSmithKline, which also helped fund the study. According to the researchers, the cancer was gone in every single one of them, undetectable by physical exam, endoscopy, PET scans, or MRI scans.

According to The New York Times, the medicine costs around $11,000 per dose. It was given to each patient once every three weeks for six months, and it works by exposing cancer cells to the immune system, allowing it to recognise and eliminate 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.”

The patients continued to show no signs of cancer after six months or more of follow-up — without the need for standard treatments such as surgery, radiation, or chemotherapy — and the cancer has not returned in any of the patients, who have now been cancer-free for 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.”

The study also revealed that none of the individuals experienced any major negative effects.

In an MSK news release, Dr. Andrea Cercek, a medical oncologist and primary investigator in the study, said, “Surgery and radiation have permanent effects on fertility, sexual health, bowel and bladder function.” “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 God, I get to keep all my normal body functions that I feared I might lose to radiation or surgery.'”

The experiment needs to be duplicated in a much larger study, according to the researchers, who point out that the current study only looked at individuals with a unique genetic signature in their tumours. However, they believe that observing total remission in 100% of the patients studied is a highly positive early sign.

It’s unclear whether the patients are cured, according to Dr. Hanna K. Sanoff of the University of North Carolina’s Lineberger Comprehensive Cancer Center, who was not involved in the study.

In an accompanying editorial, Dr. Sanoff said, “Very little is known about the duration of time needed to find out whether a clinical complete response to dostarlimab equates to cure.”

“These results are cause for great optimism,” she said.

The trial will cover roughly 30 patients, providing a more complete 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,” stated study co-leader Dr. Luis Diaz Jr., head of MSK’s solid tumour oncology division.