Nivolumab Switch Maintenance Therapy After Tyrosine Kinase Inhibitor Induction in Metastatic Renal Cell Carcinoma: A Randomized Clinical Trial by the Interdisciplinary Working Group on Renal Tumors of the German Cancer Society (NIVOSWITCH; AIO-NZK-0116ass)

The role of immune checkpoint inhibitor (ICI) maintenance therapy in metastatic renal cell carcinoma (mRCC) is undefined. To determine whether switch maintenance therapy with nivolumab improves clinical outcomes in patients with mRCC with tyrosine kinase inhibitor (TKI) sensitivity. This open-label phase 2 trial randomized patients with a partial response or stable disease after 10–12-wk TKI induction therapy to either TKI or nivolumab maintenance. Key inclusion criteria were measurable disease, clear cell histology, Eastern Cooperative Oncology Group performance status (ECOG PS) 0–2, and adequate organ function. Intravenous nivolumab 8 × 240 mg every 2 wk, followed by 480 mg every 4 wk or sunitinib 50 mg (4–2 regimen) or pazopanib 800 mg once daily orally. The primary endpoint was overall survival (OS). Secondary endpoints were the objective response rate (ORR; Response Evaluation Criteria in Solid Tumors v1.1), progression-free survival (PFS), safety (Common Terminology Criteria for Adverse Events v4.03), and patient-reported outcomes (Functional Assessment of Cancer Therapy Kidney Symptom Index). The Kaplan-Meier method, two-sided log-rank tests, and Cox regression models were used for statistical analysis. Maintenance therapy was nivolumab for 25 patients (51.0%) and TKI for 24 (48.9%). The median age was 65 yr (range 35–79). Nine patients (18.4%) were female, 31 (63.3%) had ECOG PS of 0, and 15 (30.6%) had favorable risk. OS data are immature (17 deaths, 34.7%). The ORR was 20.0% (n = 5) for nivolumab and 52.2% (n = 12) for TKI. PFS was worse with nivolumab (hazard ratio 2.57, 95% confidence interval 1.36–4.89; p = 0.003). Grade ≥3 adverse events occurred in 14 patients (56.0%) with nivolumab and 17 (70.8%) with TKI. A major limitation is early termination of our study. TKI treatment achieved superior ORR and PFS in comparison to nivolumab maintenance therapy. Our data do not indicate a role for nivolumab switch maintenance in mRCC. Patients with metastatic kidney cancer who experienced a tumor response or disease stabilization after a short period of targeted treatment with a tyrosine kinase inhibitor did not benefit from a switch to the immunotherapy drug nivolumab. Patients who continued their original treatment achieved better responses and a longer time without disease progression. This trial is registered on EudraCT as 2016-002170-13 and on ClinicalTrials.gov as NCT02959554.