A recent clinical trial of a new anti-cancer drug surprised researchers by showing that it cured every patient who participated in the trial. The results were published in June in The New England Journal of Medicine, a leading journal of medical research.
100% effective anti-cancer drug Found
Dostarlimab is an antibody-based cancer “immune checkpoint inhibitor” (immune checkpoint inhibitor), approved in the UK for the treatment of endometrial cancer. In a recent clinical trial at Memorial Sloan Kettering Cancer Center in New York, 12 patients with colorectal cancer were in remission.
Patients were treated with dostarlimab at 3-week intervals for 6 months. During this period, cancer cells cannot be detected by magnetic resonance imaging, positron-emission tomography, tissue biopsy or endoscopy!
Due to their recovery, all subjects were exempt from chemotherapy, surgery and other treatments. Luis Diaz Jr, MD, an oncologist who led the study, told The New York Times: “I believe that such remarkable results are unprecedented in the history of cancer medicine.”
Not all patients can benefit
However, this new cancer drug that has delighted patients and exhilarated researchers is not suitable for all cancer patients.
Due to the clinical experience of endometrial cancer, it was found that Dostarlimab is particularly effective in the treatment of patients with DNA mismatch repair deficiency (MMRd) in cancer cells. Therefore, this clinical trial only accepts patients to confirm that the cancer cells are MMR deficient after testing.
Is MMR defect a blessing or a curse?
MMR deficiency is also the cause of some familial hereditary cancers, and scientists’ understanding of MMR stems from a family study with hereditary cancers. In the early 1900s, American pathologist Dr. Aldred Warthin first traced the family lineage of early-onset uterine and gastrointestinal tumors.
In the mid-1960s, Dr. Henry Lynch continued to track the family and made a systematic report. In the years since, scientists around the world have noted similar familial cancers, each with slightly different rates of cancer, but characterized by colorectal, endometrial and gastric cancers.
Later, the disease was commonly referred to as Lynch syndrome, and further research gradually unraveled that Lynch syndrome was caused by mutations in genes responsible for DNA repair, such as MSH2 and MLH1.
When the cell’s ability to repair DNA is defective, the chance of genetic mutation increases and the cell becomes cancerous. However, when Dostarlimab was used to activate the immune system of cancer patients to fight cancer cells, the defect in DNA repair ability became a shroud for cancer cells, against the benefit of the patient.
Therefore, although MMR deficiency is easy to cause cancer, when the cancer immune checkpoint inhibitory drug treatment is implemented, it can help the disease to improve.
The results of this new drug trial are so perfect, the key is to select a group of patients who are most likely to benefit from Dostarlimab in advance. Due to the variability of cancer cells, each cancer patient may be suitable for different drugs.
With the rapid development of precision medicine, physicians are gradually able to finely classify cancer patients and give them the most suitable treatment drugs for individual patients, so that they can prolong their lives and even completely recover from cancer cells. However, at this stage, the price of Dostarlimab is still quite expensive. The cost of a single dose is more than 10,000 US dollars, which is not affordable for everyone.
In addition, cancer cells may still develop drug resistance and relapse. Therefore, whether Dostarlimab can exert long-term efficacy in MMR-deficient colorectal cancer patients remains to be observed.
- New cancer breakthrough drug ‘cures’ every patient
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