One study showed a 100% positive response rate in 42 patients with a certain type of rectal cancer who were treated with an experimental immunotherapy.
Rectal cancer can be treated PHOTO: Archive
Rectal cancer disappeared in all patients involved in a small clinical trial of a new immunotherapy treatment, according to updated results published this month, writes euronews.com.
The study was a collaboration between the US-based Memorial Sloan Kettering Cancer Center (MSK) and the pharmaceutical company GSK.
It looked at a new drug called dostarlimab-gxly to treat patients with a specific type of rectal cancer caused by a genetic mutation.
“As a clinician, I have seen firsthand the debilitating impact of standard dMMR rectal cancer treatment and am excited about the potential of dostarlimab-gxly in these patients,” Dr. Andrea Cercek, head of the colorectal cancer section at MSK and principal investigator of the study, said in the release.
MMRd stands for mismatch repair deficient, which means the cells have a dysfunctional DNA repair system. They account for about five percent of rectal cancers.
Current treatment for such cancer is radiotherapy, chemotherapy, surgery or a combination of these.
Treatments often have a strong impact on the patient's quality of life, with bowel disorders, bowel incontinence or sexual dysfunction, for example, according to Dr. Clélia Coutzac, an oncologist who was not involved in the study.
How does dostarlimab work?
“Because dMMRs are hypermutated tumors, they're super visible to the immune system, at first the immune system will see the cancer cells as foreign and go kill them. After a while, the cancer progresses and eventually the immune system stops still work”, Coutzac told Euronews Health.
“What works really well with these tumors is that we reactivate the system with immunotherapy, and in this case with GSK's dostarlimab, a drug that will guide the lymphocytes to recognize the cancer cells as harmful again and kill them,” she added.
Patients who underwent the six-month treatments showed a complete clinical response, with “no evidence of tumors” detected by MRI, endoscopy or digital examination during follow-up, according to the GSK statement.
Coutzac described the results as “amazing”.
Further research in progress
Before dostarlimab – also known by the brand name Jemperli – could potentially reach the market to treat MMRd rectal cancer, further research is needed.
A global study called Azur-1 is designed to further test the effectiveness of dostarlimab-gxly when used alone, instead of chemotherapy, radiotherapy or surgery, and to confirm the MSK results.
