The results of an open-label pilot study by researchers at The University of Texas MD Anderson Cancer Center in America comparing combinations of anti-PD1 (nivolumab) with either anti-CTLA-4 (ipilimumab) or anti-VEGF (bevacizumab) therapies, revealed “promising clinical activities” in people with metastatic renal cell carcinoma (mRCC). The results from the pilot study will be presented early next month at the annual meeting of the American Association of Cancer Research in Washington, D.C.
The study recruited 60 patients, of which 44 were “evaluable” for clinical responses for at least 12 weeks. The combination of nivolumab plus bevacizumab, a drug that inhibits tumour blood vessel formation, appeared to result in the highest response rate in the study, with 53% (10 of 19) of patients experiencing either a complete or partial response. This group also reported higher levels of side effects, a large proportion due to bevacizumab-related hypertension that can be easily controlled with standard medications.
In the group who received nivolumab plus ipilimumab, the response rate was 38%, while patients receiving nivolumab alone had a 42% response rate. Treatment was generally well tolerated in these two groups.
The changes in the immune system observed in this early study of patients with mRCC has raised the possibility for a larger clinical study of combination immunotherapy. The researchers said that combination therapies could lead to improved clinical activity.