| June 11, 2022
The drug has been approved in Brazil and is expected to arrive in the country in August. (Photo: Copy)
An immunotherapy-based drug was able to eliminate a rare type of tumor in the rectum in 100 percent of patients in a clinical study. The results come from scientists in New York and were published this week in the New England Journal of Medicine. The drug is expected to be launched in Brazil in August.
The drug, dostarlimab, is given every 3 weeks for 6 months. After treatment, no patients required chemotherapy or radiation therapy or surgery. Follow-up for at least 6 months after treatment (up to 25 months, just over two years). The tumor did not recur in any of them.
The study was done in 12 people with localized but advanced tumors in the rectum (the last part of the large intestine). All patients had a specific, rare molecular change that sensitized the cancer to the drug.
Dr. Rachel Riechelmann, a clinical oncologist at AC Camargo Cancer Center in São Paulo, explains that this approach, combined with immunotherapy, has been used in metastatic cases — when cancer has spread to multiple organs.
“This is the first time it has been tested on non-metastatic tumors,” the doctor said. For rectal cancer, the standard treatments are chemotherapy, radiation therapy and surgery, she explained. However, when the tumor changed in the study patients — about 1 percent to 3 percent of cases — it became susceptible to this immunotherapy.
“Drugs alone have eliminated the disease, no radiation, chemotherapy and surgery. It’s fantastic, but [o tratamento] It will target a small subset of patients in which tumors develop through this molecular alteration,” explains Riechelmann.
The oncologist added that despite the small number of patients, the fact that the change was rare makes the number large enough to consider the drug effective. Even so, more research is needed. “The more you collect, publish, and present, the better,” he said.
Dostarlimabe was approved for use in Brazil by the National Health Surveillance Agency (Anvisa) in March and is expected to be available in August, according to manufacturer GSK.
Currently, however, the approval is only for a type of also rare cancer of the lining of the uterus (the innermost layer of the uterus); rectal cancer remains unapproved.
But Rachel Riechelmann explained that the same changes seen in rectal cancers in U.S. patients can occur, for example, in the endometrium — so the results would be similar.
“All the immunotherapies we have in Brazil work on this rare molecular alteration, which is present in rectal cancer, but probably in about 1 to 3 percent of all solid tumors,” he explained.
In the US, the drug was approved in August 2021. There, it can be used to treat any type of advanced solid tumor that, even after initial treatment, continues to progress and has no other treatment options. General approval came four months after an initial authorization — also approved for only one type of endometrial cancer.
ACCamargo’s Rachel Riechelmann explained that even though the drug is licensed for rectal cancer, it is difficult to obtain. This is because the vast majority of cancer immunotherapies, even those already used in Brazil, are not available in SUS – the first immunotherapies were only approved in 2020 and for melanoma, a type of skin cancer. For rectal cancer, treatment in the public system remains traditional (chemotherapy, radiotherapy, and surgery).
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