A recent phase 2 study evaluated the combination of bevacizumab with temsirolimus in 39 patients with metastatic renal cell carcinoma (mRCC) after failure of first-line treatment with a vascular endothelial growth factor (VEGF) receptor inhibitor.
After 6 months, 50.9% of patients were progression-free and median time to progression of the disease was 6.8 months. The objective response rate was 27% and median overall survival was 18.2 months.
The safety profile of the combination was poor, and the most frequently reported adverse events were metabolic, gastrointestinal, and infections, leading to a number of patients coming off treatment.
The study confirms the efficacy of combining a VEGF inhibitor (bevacizumab) with a mammalian target of rapamycin (mTOR) inhibitor (temsirolimus). However, the toxicity of the combination was considerable and led to a high rate of treatment discontinuations.