A small US clinical trial of an experimental drug has produced unexpected and incredible results.

18 patients, who had been diagnosed with rectal cancer, took part in a six-month trial of Dostarlimab and all entered remission within this period. 

The cancer vanished in every patient and was completely undetectable by physical exam, PET or M.R.I scans or by endoscopy according to a New England Journal of Medicine study. 

The trial, which was sponsored by the drug company GlaxoSmithKline, has produced ground-breaking results and it's thought to be the first time in the history of the condition. 

The Northern Echo: A doctor and patient. Credit: PAA doctor and patient. Credit: PA

US drug trial obliterates cancer in all patients

The author of the paper, Dr. Luis A. Diaz Jr. of Memorial Sloan Kettering Cancer Center, explained that he was not aware of any other study that completely removed the cancer of every patient involved. 

“I believe this is the first time this has happened in the history of cancer,” Dr. Diaz said to the New York Times.

The cancer patients had previously faced gruelling treatments including radiation, chemotherapy and likely major surgery that could cause urinary, bowel and sexual disfunction. 

Some patients are likely to need colostomy bags.

It was expected that the patients would return to these harrowing procedures following the end of the trial since remission was unlikely.

However, no further treatment was needed and none of the patients have experienced clinically significant complications following the study. 

Co-author of the paper that was presented at the annual meeting of the American Society of Clinical Oncology, Memorial Sloan Kettering Cancer Center oncologist Dr Andrea Cercek remarked that: “there were a lot of happy tears".

The patients received the Dostarlimab medication, which costs $11,000 per dose, every three weeks for six months.

The lack of significant side effects could be a result of "plain different" cancers or that "they did not treat enough patients" according to a colorectal cancer specialist at the University of California, Dr. Alan P. Venook, who was not involved in the trial.

Dr Kimmie Ng, who is a colorectal cancer expert at Harvard Medical School, commented that although the results were indeed “remarkable” and “unprecedented,” they would need to be replicated.