Updated results from clinical trials presented at the American Society of Clinical Oncology (ASCO) 2024 conference suggest that immunotherapy drugs, such as Jemperli (dostarlimab-gxly) and pembrolizumab, could significantly improve survival rates for patients with certain types of bowel cancer. These findings come as a potential game-changer in the field of cancer treatment.
Jemperli, developed by GSK, has shown unprecedented results in treating 100% of patients with locally advanced mismatch repair deficient (dMMR) rectal cancer. In a trial led by Memorial Sloan Kettering Cancer Centre, all 42 patients had a complete response to treatment, with no evidence of disease on scans. The first 24 patients have been followed up for an average of 26.3 months and sustained clinical complete response has been observed.
Pembrolizumab, already available on the NHS, could also triple survival chances for some bowel cancer patients according to a study led by University College London (UCL). In this trial, 59% of patients' tumours shrank so much that there were no signs of disease when the affected section of their bowel was removed. This could significantly improve long-term survival rates for these patients.
Both Jemperli and pembrolizumab work by boosting the immune system's ability to attack cancer cells. They do this by blocking the action of a molecule called PD-1 that hides the cancer from the immune system, allowing it to be identified and killed by the body itself.
These findings are particularly significant for patients with bulky high-risk tumours who may otherwise require surgery and chemotherapy. The potential for these immunotherapies to replace or reduce the need for such treatments could significantly improve quality of life for many patients.
Further registrational studies of dostarlimab-gxly in dMMR/microsatellite instability-high rectal and colorectal cancer are currently recruiting. These studies will provide more information on the safety and efficacy of this treatment in a wider patient population.
