Rectal cancer disappeared in all patients who participated in a small clinical trial of a new immunotherapy method, according to results published this month. The research was carried out in cooperation with the American Memorial Sloan Kettering (MSK) oncology center and the pharmaceutical company GSK. A new drug, dostarlimab-gxly, was tested for the treatment of rectal cancer caused by a genetic mutation.
“As a physician, I am excited about the MMRd cancer treatment dostarlimab-gxly for patients with rectal cancer,” said Dr. Andrea Cercek, head of the colorectal cancer department at MSK.
“Mismatch repair deficient” (MMRd) refers to a condition in which the mismatch repair (MMR) system of cells is not functioning properly. The MMR system is responsible for identifying and repairing errors that occur during DNA replication. When this system is deficient or defective, it fails to correct these errors, leading to an accumulation of mutations within the cell’s DNA. This can contribute to the development and progression of certain types of cancer, including some forms of rectal cancer. MMRd is often associated with specific genetic mutations that disrupt the normal repair process. Currently, the pathology is treated with radiotherapy, chemotherapy, surgery, or a combination of these approaches.
According to Dr. Clelia Kutzak, who did not participate in the research, the therapy often has a very negative impact on the patient’s quality of life, causing intestinal disorders and sexual dysfunction.
“In such tumors, it is effective to reactivate the immune system with the help of immunotherapy. In this case, dostarlimab is a drug that allows lymphocytes to re-recognize cancer cells as harmful and destroy them,” explained Dr. Kutzak in an interview with Euronews Health.
Patients who received six months of treatment had a complete clinical response, with “no evidence of tumor” on MRI, endoscopy, or digital imaging. Kutzak called the results “shocking.”
Additional tests are needed before dostarlimab reaches the market. The global research study, named Azur-1, aims to further verify the effectiveness of the drug as an alternative to chemotherapy or surgical intervention, as well as to confirm the results obtained at MSK.
A clinical study showed a 100 percent positive result of experimental immunotherapy in 42 patients with a specific type of rectal cancer.