June 2022: A small study of rectal cancer patients yielded extraordinary results: 100 percent of the individuals were in remission. The results were published in The New England Journal of Medicine this week.
The trial was funded by GlaxoSmithKline, which produced the medicine dostarlimab, according to the New York Times. For six months, patients in the trial were given dostarlimab, an immunotherapy drug that stimulates patients’ immune systems to target their malignancies.
According to the study, all 12 people had comparable mutations in mismatch repair-deficient colorectal cancer, which occurs in roughly 5 to 10% of colorectal malignancies. Standard chemotherapy has a dismal prognosis for these malignancies.
“They lack a gene that allows them to repair their DNA,” doctor Andrea Cercek, a coauthor of the study from Memorial Sloan Kettering Disease Center, told CNN. “As a result, they have many, many mutations, and the immune system detects the cancer as foreign.” “When we administer immunotherapy, like dostarlimab, we’re essentially just revving up the immune system so it can see the cancer and kill it.”
Dostarlimab is an antibody that targets the protein PD-1, which stands for programmed cell death 1. PD-1 is a protein found on the surface of immune system T-cells that helps the body recognise and destroy cancer cells. Cancer cells can then create chemicals that disrupt PD-1, allowing them to slip past the immune system’s detection. Dostarlimab works by preventing cancer cells from evading the immune system, allowing the immune system to discover and kill cancer cells. The researchers intended to follow up on the dostarlimab treatment with normal chemoradiotherapy and surgery, but the patients didn’t require it. According to the study, all 12 subjects who completed the dostarlimab treatment and had a 6-month follow-up had no detected cancer cells or major side effects. According to a statement, no cases of advancement or recurrence have been observed even after 25 months.
Traditional colon cancer therapies can have life-changing consequences, according to Hanna Sanoff of the University of North Carolina’s Lineberger Comprehensive Cancer Center, who was not involved in the study but wrote an editorial about it.
“Both surgery and radiation have long-term implications for fertility, sexual health, and bowel and bladder function. “The consequences for quality of life are significant, particularly for women whose reproductive potential would be harmed by current treatment,” Cercek said in the statement. “With the increased incidence of rectal cancer among young persons, this method could have a significant impact.”
Experts warn that the experiment was limited, and it’s too early to tell if the patients will remain in remission. Sanoff adds in the editorial that even individuals who have had a complete response to radiation and chemotherapy can experience cancer relapse in 20 to 30 percent of cases when the malignancy is handled nonoperatively.
PD-1 is involved in a larger biological mechanism known as “checkpoint inhibition,” which functions as an on/off switch for immune cells. One of the most active areas of study in oncology right now is targeting PD-1 and other aspects of checkpoint inhibition for cancer treatment.
“These findings are grounds for considerable optimism,” Sanoff says, “but such an approach cannot yet supersede our existing curative treatment approach.” The research should be duplicated, he adds.
She tells NPR, “What I’d really like us to do is obtain a broader trial where this medicine is utilised in a much more diversified population to discover what the real, true response rate is going to be.” “It’s not going to be a hundred percent.” I’m hoping I’ll be able to hold my tongue on that in the future, but I doubt it. And when we see what the true response rate is, I believe we’ll be able to do this on a regular basis.”