Combining Opdivo (nivolumab) with the anti-VEGF drug Avastin (bevacizumab) may be a promising treatment approach for patients with metastatic renal cell carcinoma (mRCC), according to data from a Phase 1 clinical trial.
The findings were presented April 4 at the American Association of Cancer Research Annual Meeting 2017, in Washington, D.C., by researchers at The University of Texas MD Anderson Cancer Center. They raise the possibility of conducting a larger clinical study evaluating this combination in mRCC patients.
Immune checkpoint inhibitors like Opdivo and Yervoy were known to have clinical activity against mRCC, but the number of patients who respond to such therapies is low.
Avastin, a drug that impairs the formation of new blood vessels, is a standard therapy for mRCC, but it also has a low response rate.
This led researchers to hypothesize that combining these therapies could improve their clinical activity, as well as the number of patients whose tumors shrunk.
Sixty mRCC patients who had not received prior treatment with Yervoy, Opdivo, or Avastin were included in the study. Patients were then categorized based on their planned surgical procedure or biopsy, and randomized to receive either Opdivo alone, Opdivo plus Yervoy, or Opdivo plus Avastin.
After receiving the assigned treatment for six weeks, patients underwent surgery to remove the remaining tumors, and then were placed on Opdivo maintenance therapy for up to two years, or until disease progression or unacceptable toxicity. Patients were followed for a median duration of 17 weeks.
“Out of 60 patients treated, 44 were evaluable for clinical responses post-treatment and/or procedures,” Jianjun Gao, MD, PhD, assistant professor of Genitourinary Medical Oncology, said in a press release. “We observed a response rate of 53 percent for patients treated with nivolumab plus bevacizumab.”
The study revealed that among patients receiving Opdivo monotherapy, 42% responded to the treatment, and 33% had stable disease.
While treatment with Opdivo plus Yervoy did not improve these rates, which were 38% and 8%, respectively, combining Opdivo with Avastin showed promising results for mRCC patients.
In this group of patients, 53% experience either a partial or complete response, and 16% had stable disease. This accounted for a disease control rate of 69%.
The team reported that the Opdivo plus Avastin combination had the highest rates of adverse events, but pointed out that most patients had Avastin-related hypertension, which was controlled easily with standard therapies.
“These findings are significant since a signal to indicate efficacy for the nivolumab plus bevacizumab arm could provide data to design a larger study,” said Padmanee Sharma, MD, PhD, professor of Genitourinary Medical Oncology.