Researchers are interested in the bacteria in our gut (the microbiome) and wanted to see if the different types of gut bacteria could affect survival for patients with kidney cancer that has spread. Some studies showed that a link between the gut bacteria and side effects, like diarrhoea with tyrosine kinase inhibitors (TKIs), e.g., sunitinib. A subsequent study showed a link between immunotherapies and the gut bacteria in terms of survival and response to treatment.
In a study published in Nature Medicine, a live bacterial product, called CBM 588, was added to the ipilimumab plus nivolumab combination and compared to the combination alone. There were 30 patients in the study who had not previously received treatment for their kidney cancer. The amount of CBM 588 was tailored to the needs of each individual patient in the study.
They showed that the time to when the treatment stopped working and the cancer started growing again (progression-free survival) was significantly longer in patients who were given the nivolumab–ipilimumab combination plus CBM 588 compared to those who did not receive CBM 588 (12.7 months versus 2.5 months). Also, the cancer responded to treatment by getting smaller in 58% of patients in the ipilimumab-nivolumab plus CBM 588 group compared to 20% in the ipilimumab-nivolumab group.
This study showed that CBM 588 improves survival and response to treatment in patient with metastatic kidney cancer who are treated with the nivolumab–ipilimumab combination.