Keytruda Prolongs Time Without Cancer Signs, Symptoms in Clear Cell RCC

Patients with clear cell renal cell carcinoma (RCC), the most common type of kidney cancer, who were treated with adjuvant Keytruda (pembrolizumab) had improved survival outcomes compared with placebo, research showed.

Data from an exploratory analysis of the phase 3 KEYNOTE-564 study were presented at the 2023 Kidney Cancer Research Summit.

The estimated median disease-free survival (the time after treatment that a patient with cancer survives without signs or symptoms of that cancer) for patients with intermediate-risk disease was not reached (meaning not enough people experienced disease-related events for this to be assessed yet) in either the Keytruda arm or the placebo arm. The 24-month disease-free survival rates in each respective arm were 81.5% versus 72.4%.

For those with high-risk disease, the estimated median disease-free survival was not reached in the Keytruda arm versus 40.5 months in the placebo arm, with 24-month disease-free survival rates of 65% versus 55.9% in each respective arm.

The estimated median disease-free survival among patients following nephrectomy (surgery to remove the entire kidney or a portion of it) and complete resection of metastasis was not reached with Keytruda versus 11.6 months with placebo, and the corresponding 24-month disease-free survival rates of 78.4% versus 37.9% in each arm.

The disease-free survival and distant metastasis-free survival (the time after treatment that a patient with cancer survives without the cancer spreading to a distant area or organ) benefits observed with Keytruda extended across all subgroups based on disease risk primary tumor stage and lymph node involvement. The investigators advised interpreting these data with caution based on the small sample size of some patient subgroups.

In this subgroup analysis of the phase 3 KEYNOTE-564 study, investigators assessed whether risk groups and disease stage correlated with the efficacy of adjuvant (additional treatment after primary treatment) Keytruda among those with clear cell RCC. Patients were randomly assigned to receive either Keytruda (496 patients) or matched placebo (498 patients).

Researchers focused on several outcomes throughout the study including disease-free survival and distant metastasis-free survival across patient subgroups. Follow-up was conducted for a median of 30.1 months.

Patients with clear cell RCC and no receipt of prior systemic therapy were eligible for enrollment on the trial. Those with an intermediate-high risk of recurrence following nephrectomy, complete resection of metastasis following nephrectomy and an ECOG performance status of 0 or 1 (meaning they were either fully active or restricted in strenuous activity) were also able to enroll.

In the Keytruda and placebo arms, respectively, most patients had intermediate-risk disease (73.6% versus 75.1%), followed by high-risk disease (20.5% versus 19.1%) and complete resection of metastasis following nephrectomy (5.9% versus 5.8%). Most patients in each respective arm had stage 3 disease (87.3% versus 88%) followed by stage 4 (8.3% versus 8.2%) and stage 2 disease (4.4% versus 3.8%).

Across the intermediate-risk, high-risk and completely resected metastasis following nephrectomy groups in the Keytruda and placebo arms, male patients made up anywhere from 61% to 82.8% of the population. Additionally, 34% to 99.4% of patients had an ECOG performance status of 0, and 91.6% to 96.8% underwent radical nephrectomy.

Across the risk subgroups, 24.1% to 95.5% of patients had a primary tumor size of T3. Additionally, anywhere from 37.9% to 51.7% of patients had grade 3 tumors, and 71% to 100% had N0 lymph node staging.

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