A small clinical trial conducted by memorial Sloan Kettering cancer center in New York found that all 14 rectal cancer patients who received experimental immunotherapy recovered. All of these subjects had locally advanced rectal cancer with a rare mutation (mismatch repair defect, dmmr). The researchers said this was the first time in the history of cancer treatment. The results were published in the New England Journal of medicine.
The patient received dostarlimab, an immunotherapeutic drug developed by GlaxoSmithKline. The researchers said that the cancer disappeared miraculously in every patient, and the cancer could not be detected by physical examination, endoscopy, PET scan or MRI scan.
According to the British times, the cost of each dose of the drug is about 11000 US dollars (about 73615 yuan). The patients were given it every 3 weeks for 6 months.
The researchers said that human immune cells contain a protective measure called "checkpoints" to prevent them from attacking normal cells. But cancer cells can affect this protection and shut down immune cells, allowing tumors to hide and grow. This new method is an immunotherapy that enables the immune system to eliminate cancer cells by blocking the "don't eat me" signal. This treatment is targeted at the rectal cancer subtype where the DNA repair system does not work. When the repair system does not work, more errors will be made in the protein, and the immune system will recognize these errors and kill the cancer cells.
After a follow-up of 6 to 25 months after the end of the experiment, all the patients involved in the study showed no signs of cancer recurrence, and no further standard treatment such as surgery, radiotherapy and chemotherapy was required. Another surprise of the study was that none of the patients had serious side effects.
The researchers said that the results were surprising. All patients in the clinical trial responded to the drug, which was almost unheard of. They coined the term "immunoablation" for this method of targeting specific tumors with immunotherapy alone, which means "using immunotherapy instead of surgery, chemotherapy and radiotherapy to eliminate cancer".
The researchers said that rectal cancer surgery and radiotherapy have a permanent impact on fertility, sexual health, intestinal and bladder function, and have a huge impact on the quality of life. As the incidence rate of rectal cancer in young people increases, new methods may have a significant impact.
The researchers agreed that this trial now needs to be repeated in larger studies, and pointed out that this small study only focuses on patients with rare genetic characteristics in tumors. But they said that seeing complete remission in 100% of the patients was a very promising early signal.