Cabozantinib and nivolumab with or without live bacterial supplementation in metastatic renal cell carcinoma: a randomized phase 1 trial

Study answer

What this study found

Adding CBM588 to cabozantinib plus nivolumab showed a signal of clinical benefit, but it did not alter gut Bifidobacterium abundance or alpha diversity. Objective response rate was higher with CBM588 than control: 74% (14 of 19) versus 20% (2 of 10), P = 0.01. Six-month progression-free survival was also higher in the CBM588 group: 84% (16 of 19) versus 60% (6 of 10), and clinical benefit occurred in 80% (16 of 20) versus 60% (6 of 10). The regimen did not show excess toxicity overall, although grade greater than or equal to 3 adverse events were reported in 40% versus 30% of participants…

Study & population

Randomized phase 1, single-center trial in treatment-naive adults with locally advanced or metastatic renal cell carcinoma, including clear cell, papillary, or sarcomatoid components and adequate performance status.

Intervention

CBM588, a live bacterial product (Clostridium butyricum), was given at 80 mg by mouth twice daily and continued indefinitely while participants remained on protocol.

Key limitation

This was a small phase 1, single-center study with only 20 participants in the active arm and limited power to assess efficacy or safety.

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Original abstract