Promoting to the front line two drugs normally used in rearguard action to treat advanced renal cell carcinoma (RCC) – nivolumab (Opdivo) and cabozantinib (Cabometyx) – doubled overall response rates and progression-free survival (PFS) and significantly improved overall survival (OS), compared with first-line sunitinib (Sutent), investigators in the Checkmate 9ER trial reported.
Median PFS among patients with advanced RCC, which was the trial’s primary endpoint, was 16.6 months with nivolumab plus cabozantinib, compared with 8.3 months with sunitinib, translating into a hazard ratio of 0.51 for the combination (P < .0001). The median follow-up was 18.1 months.
Median OS had not been reached in either arm at the time of data cutoff, but the survival curves at the time of the analysis clearly favored nivolumab-cabozatinib, with an HR for death of .060 (P = .0010), said Tony K. Choueri, MD, from the Dana-Farber Cancer Institute in Boston.
“With expanding options in our patients with advanced RCC, the overall efficacy, safety, and quality-of-life benefit, as well as individual patient characteristics, are very important considerations when you select appropriate therapy,” he said in a press briefing prior to his presentation of the data in a presidential symposium at the European Society of Medical Oncology Virtual Congress 2020.
Although the nivolumab-cabozantinib combination therapy looks good, it’s late to the game, commented Dominik Berthold, MD, from the Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland, the invited discussant for the briefing.
“The question is, what’s the only drawback of this trial? It’s probably the fact that it’s not first in class in this situation,” he said.
Dr. Berthold noted that nivolumab-cabozantinib, if approved for the frontline setting, will join the combination of the tyrosine kinase inhibitor (TKI) axitinib (Inlyta) plus pembrolizumab (Keytruda), which, as previously reported, was associated with a nearly 50% reduction in the risk for death in the KEYNOTE-426 trial. This combination was approved by the Food and Drug Administration for the frontline setting in April 2019.
As shown in the CheckMate-214 study, the combination of the programmed cell death protein–1 (PD-1) inhibitor nivolumab with the CTLA-4 inhibitor ipilimumab (Yervoy) was associated with significantly higher objective response rates and OS rates compared with sunitinib. This combination was approved by the FDA in April 2018 as first-line therapy for patients with advanced intermediate- or poor-risk RCC.
CheckMate 9ER details
A total of 651 patients with previously untreated advanced or metastatic RCC that had a clear cell component in all International Metastatic RCC Database Consortium risk groups were enrolled and randomly assigned to receive either intravenous nivolumab at 240 mg every 2 weeks plus oral cabozantinib at 40 mg daily or oral sunitinib at 50 mg daily in cycles of 4 weeks on therapy/2 weeks off therapy. Patients were treated until disease progression or unacceptable toxicities occurred.
The primary PFS endpoint and the secondary OS endpoint both favored the combination, as did the objective response rate, which was 55.7% with nivolumab-cabozantinib versus 27.1% with sunitinib (P < .0001).
Complete responses were seen in 8% of patients who received the combination versus 4.6% with the patients who received sunitinib. Partial responses were seen in 47.7% and 22.6%, respectively.
Patients generally tolerated the combination. The incidence of the most common high-grade treatment-emergent adverse events and other adverse events of any grade was similar to that seen with sunitinib, Dr. Choueri said.
The rates of treatment-related events that led to discontinuation was 3.1% among patients who received the combination, 5.6% among patients who received the nivolumab component only, and 6.6% among patients who received cabozantinib only. It was 8.8% among patients who received sunitinib. More than 50% of patients in the combination arm needed a dose reduction of nivolumab-cabozantinib because of adverse events, however.
“Overall, it seems that the combination has a somewhat manageable safety profile in patients with advanced RCC,” Dr. Choueri said.
Patient-reported quality of life, as measured by the National Comprehensive Cancer Network/Functional Assessment of Cancer Therapy–Kidney Symptom Index 19 total score, was an exploratory endpoint. It was maintained over time with the combination but deteriorated over time with sunitinib, with statistically significant differences between the study arms at most time points to 91 weeks, he reported.