The European Society for Medical Oncology (ESMO) holds its annual primary meeting to provide an opportunity for researchers from across the world to come together to discuss the latest, exciting advances in cancer treatment. This year, ESMO took place in Madrid, Spain from October 23 to October 27, 2026. ESMO 2026 brought a promising update in colorectal cancer.
About the INCA33890 trial
For many people with colorectal cancer, immunotherapy can be an important treatment option. However, a common type called microsatellite-stable (MSS) colorectal cancer often doesn’t respond well to currently available immunotherapies. Researchers are exploring new ways to help the immune system recognize and attack these tumors, including a new experimental drug called INCA33890.
Early clinical trial findings suggest that INCA33890 may help treat MSS colorectal cancer when combined with standard treatments. While more research is needed, the results offer a reason for cautious optimism about expanding treatment options for people whose cancer may be difficult to treat.
What did the researchers find?
The findings came from an early-stage clinical trial that tested INCA33890 alongside standard cancer treatments in people with advanced or metastatic MSS colorectal cancer. The researchers looked at patients receiving their first treatment for metastatic disease as well as those who had already received several treatments.
Among 42 patients whose cancer had not yet been treated for metastatic disease, 71.4% experienced a reduction in the size of their tumors. In this group, all patients had either tumor shrinkage or stable disease, meaning their cancer didn’t grow during the assessment. Among 39 patients who had received at least two previous treatment regimens, 28.2% experienced tumor shrinkage when INCA33890 was combined with bevacizumab, a targeted cancer drug. These results are encouraging because they suggest the treatment may have activity both earlier in treatment and after other therapies have been tried.
How does INCA33890 work?
INCA33890 is an experimental immunotherapy designed to help the immune system better recognize and attack cancer cells. It targets two proteins involved in controlling the immune response. By targeting both pathways, researchers hope to make the environment around a tumor more favorable for the immune system to fight cancer.
This approach is particularly important for MSS colorectal cancer, which often does not respond well to existing immunotherapies. Finding a way to help the immune system overcome this resistance could potentially expand treatment options for people with this type of cancer.
What about side effects?
Researchers reported no dose-limiting toxicities, meaning no side effects that prevented the study from continuing at the doses being tested. However, side effects were common, particularly among patients receiving INCA33890 with chemotherapy and bevacizumab. These included nerve-related symptoms, low white blood cell counts, mouth sores, nausea, diarrhea, and fatigue. Some patients experienced serious side effects, so further research is needed to better understand the treatment’s safety and how its side effects can be managed.
What does this mean for people with colorectal cancer?
These early findings offer hope that combining immunotherapy with existing treatments may provide another approach for people with MSS colorectal cancer, including those whose disease has spread or who have already tried other treatments. However, this was a relatively small, early-stage study, and the results do not yet show whether INCA33890 helps people live longer or keeps their cancer under control for longer than standard treatment alone.
A larger phase 3 clinical trial is now evaluating INCA33890 with chemotherapy and bevacizumab compared with the same standard treatments without INCA33890 in people receiving their first treatment for metastatic MSS colorectal cancer. Until more results are available, INCA33890 remains an investigational treatment and isn’t yet an established standard of care.
Disclaimer: The information provided in this article is for informational purposes only and is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Outcomes4Me is not acting as your caregiver, and any suggestions or guidance offered should not replace the advice of your healthcare provider or qualified medical professional. Always seek the guidance of your physician or other qualified health provider with any questions you may have regarding a medical condition.
