medwireNews: Postoperative treatment with pembrolizumab significantly improves the disease-free survival (DFS) of patients with high-risk, clear cell renal cell carcinoma (RCC) relative to placebo, show trial data.
“KEYNOTE-564 is the first positive phase 3 study of an adjuvant immunotherapy for patients with renal cell cancer,” and the findings support the PD-1 inhibitor “as a potential new standard of care” in the RCC adjuvant setting, presenting author Toni Choueiri (Dana-Farber Cancer Institute, Boston, Massachusetts, USA) told the press at the 2021 ASCO Annual Meeting.
Toni Choueiri outlines the results of the phase 3 KEYNOTE-564 trial showing the benefit of adjuvant treatment with pembrolizumab in patients with high-risk renal cell carcinoma (3:03).
The prespecified interim analysis, conducted at a median follow-up of around 24 months, showed that the primary endpoint of investigator-assessed DFS was met. Specifically, adjuvant pembrolizumab reduced the risk for recurrence or death by a significant 32% versus placebo, with the median unreached in both study arms at data cutoff.
The estimated 12-month DFS rates in the pembrolizumab and placebo groups were 85.7% and 76.2%, respectively, while the corresponding 24-month rates were 77.3% and 68.1%.
The double-blind trial enrolled 994 patients with completely resected RCC who were at high risk for recurrence in line with the criteria outlined below:
- pT2, grade 4 or sarcomatoid, N0, M0 disease;
- pT3 or pT4, any grade, N0, M0 disease;
- any pT, any grade, N+, M0 disease; or
- M1 but with no evidence of disease after surgery.
Participants were randomly assigned to receive either adjuvant pembrolizumab 200 mg every 3 weeks or placebo for up to a year.
Overall survival (OS) data were immature at the time of analysis, with just 26% of events having occurred, said Choueiri. But he noted that pembrolizumab treatment was associated with a 46% reduction in the risk for death compared with placebo, albeit without meeting the criteria for statistical significance.
The preliminary estimated OS rate at 24 months was 96.6% among pembrolizumab-treated patients and 93.5% among those given placebo.
“Additional follow-up is planned for this key secondary endpoint,” highlighted the presenter.
Reporting on the adverse event (AE) profile of pembrolizumab, he said that the findings “were in line with expectations overall, without any new safety signals.”
All-cause AEs of grade 3–5 occurred in 32.4% of patients in the pembrolizumab group and 17.7% of those in the placebo group, while the rates of treatment-related AEs of this severity were 18.9% and 1.2%, respectively. There were no deaths due to treatment-related AEs in either study arm.
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