Dr Barata on Immunotherapy Treatment and the Gut Microbiome in Kidney Cancer

Pedro Barata, MD, MSc, director, GU Medical Oncology Research Program, University Hospitals Seidman Cancer Center, associate professor, Medicine, Case Western Reserve University, Case Comprehensive Cancer Center, discusses important considerations regarding the relationship between immunotherapy treatment and the gut microbiome when treating patients with kidney cancer.

When discussing treatment with immunotherapy in patients with renal cell carcinoma (RCC), it is important to credit the group of investigators from City of Hope that has led efforts to define the role of the microbiome in immunotherapy treatment in this population, Barata begins. These investigators conducted a proof-of-concept phase 1 clinical trial (NCT03829111) that investigated the use of the live bacterial product CBM588 in addition to treatment with ipilimumab (Yervoy) and nivolumab (Opdivo) in patients with stage IV or advanced kidney cancer. This trial aimed to use CBM588 to optimize the efficacy of the immunotherapy combination, Barata explains.

Notably, patients who were treated with CBM588 plus immunotherapy experienced improved progression-free survival (PFS) compared with those who received ipilimumab and nivolumab alone. At a median follow-up of 12.2 months, the median PFS was 12.7 months and 2.5 months in the investigational and immunotherapy alone arms, respectively (HR, 0.15; 95% CI, 0.05-0.47; P < 0.001).

Moving forward, continued research with the bacterium CBM588 plus immunotherapy is necessary to confirm thebenefit of this combination, he continues. Researchers also need to further understand how treatment with this combination affects the gut microbiome and whether those effects translate to clinical improvement in the RCC population, Barata explains. Because of this research need, the phase 3 confirmatory trial for this investigation is being planned, he adds. That trial is one example of several investigations with bacterial products in combination with immunotherapy that will read out in the years to come in the kidney cancer treatment landscape, Barata notes. Investigating this combination in patients with RCC will help researchers understand whether CBM588 and other bacterium can optimize the activity of immunotherapy in this population, Barata concludes.