Colorectal cancer is a common form of cancer that affects the colon and rectum, and is the third most common cancer worldwide and the second leading cause of cancer deaths. Various treatments for colorectal cancer include surgery, radiotherapy, chemotherapy, and immunotherapy. However, the effectiveness of treatment depends on the type of colorectal cancer a person has. A recent phase 1 trial has found promising results with two monoclonal antibodies that could be effective against a common form of colorectal cancer that has historically not responded to immunotherapy.
According to the World Health Organization, around 10% of cancers worldwide are colorectal cancer, with most cases diagnosed in individuals over the age of 50. Various risk factors, including genetic and environmental causes, contribute to the development of colorectal cancer. Some of these risk factors include male sex, a diet low in fiber and high in animal protein, smoking and alcohol consumption, obesity, and inflammatory bowel disease. Early detection of colorectal cancer is crucial for effective treatment, which may involve surgery, radiation therapy, chemotherapy, or immunotherapy.
Immunotherapy has shown to be effective in some types of colorectal cancer, but a phase 1 trial has now found that a combination of two monoclonal antibodies, botensilimab and balstilimab, was successful in treating 61% of people with the advanced form of colorectal cancer, known as MSS mCRC. This form of cancer has previously been resistant to immunotherapy, making the findings of this trial particularly significant. The study, published in Nature Medicine, is a step towards more effective treatment for individuals with this specific type of colorectal cancer.
The research involved recruiting 148 patients with bowel tumors that had spread to other parts of the body and had undergone multiple previous treatments. The patients were treated with escalating doses of botensilimab followed by a combination of botensilimab and balstilimab. Of the 101 patients who completed the six-month follow-up, 61% showed positive responses to the treatment. However, the study also found that patients with active liver metastases had lower response rates and survival times, indicating the need for further investigation in such cases.
While the combination of botensilimab and balstilimab showed promising results, it is essential to conduct larger studies to verify these findings and understand the long-term effectiveness of this treatment. Immunotherapy is generally better tolerated than other treatments for colorectal cancer, with fewer severe side effects reported. Despite some participants experiencing treatment-related adverse effects like fatigue and diarrhea, no treatment-related deaths occurred during the study, indicating the safety and tolerability of the combination therapy.
The study’s lead researcher, Prof. Justin Stebbing, expressed optimism about the potential impact of this trial on the prognosis of individuals with MSS mCRC. The trial’s findings could lead to a significant advancement in the treatment of colorectal cancer, particularly for those with the advanced form of the disease that has not responded well to existing therapies. Further research and clinical trials are needed to validate these results and determine the broader applicability of the combination of monoclonal antibodies in treating colorectal cancer. Despite the challenges, this study offers hope for a more effective and potentially life-saving treatment option for individuals with MSS mCRC.
