Conditional survival and long-term efficacy with nivolumab plus ipilimumab versus sunitinib in patients with advanced renal cell carcinoma

BACKGROUND

Conditional survival estimates provide critical prognostic information for patients with advanced renal cell carcinoma (aRCC). Efficacy, safety, and conditional survival outcomes were assessed in CheckMate 214 (ClinicalTrials.gov identifier NCT02231749) with a minimum follow-up of 5 years.

METHODS

Patients with untreated aRCC were randomized to receive nivolumab (NIVO) (3 mg/kg) plus ipilimumab (IPI) (1 mg/kg) every 3 weeks for 4 cycles, then either NIVO monotherapy or sunitinib (SUN) (50 mg) daily (four 6-week cycles). Efficacy was assessed in intent-to-treat, International Metastatic Renal Cell Carcinoma Database Consortium intermediate-risk/poor-risk, and favorable-risk populations. Conditional survival outcomes (the probability of remaining alive, progression free, or in response 2 years beyond a specified landmark) were analyzed.

RESULTS

The median follow-up was 67.7 months; overall survival (median, 55.7 vs 38.4 months; hazard ratio, 0.72), progression-free survival (median, 12.3 vs 12.3 months; hazard ratio, 0.86), and objective response (39.3% vs 32.4%) benefits were maintained with NIVO+IPI versus SUN, respectively, in intent-to-treat patients (N = 550 vs 546). Point estimates for 2-year conditional overall survival beyond the 3-year landmark were higher with NIVO+IPI versus SUN (intent-to-treat patients, 81% vs 72%; intermediate-risk/poor-risk patients, 79% vs 72%; favorable-risk patients, 85% vs 72%). Conditional progression-free survival and response point estimates were also higher beyond 3 years with NIVO+IPI. Point estimates for conditional overall survival were higher or remained steady at each subsequent year of survival with NIVO+IPI in patients stratified by tumor programmed death ligand 1 expression, grade ≥3 immune-mediated adverse event experience, body mass index, and age.

CONCLUSIONS

Durable clinical benefits were observed with NIVO+IPI versus SUN at 5 years, the longest phase 3 follow-up for a first-line checkpoint inhibitor-based combination in patients with aRCC. Conditional estimates indicate that most patients who remained alive or in response with NIVO+IPI at 3 years remained so at 5 years.

First-line Nivolumab plus Ipilimumab Versus Sunitinib in Patients Without Nephrectomy and With an Evaluable Primary Renal Tumor in the CheckMate 214 Trial

We present an exploratory post hoc analysis from the phase 3 CheckMate 214 trial of first-line nivolumab plus ipilimumab (NIVO+IPI) versus sunitinib in a subgroup of 108 patients with advanced renal cell carcinoma (aRCC) without prior nephrectomy and with an evaluable primary tumor, a population under-represented in clinical trials. Patients with clear cell aRCC were randomized to NIVO+IPI every 3 wk for four doses followed by NIVO monotherapy, or sunitinib every day for 4 wk (6-wk cycle). Overall survival (OS), progression-free survival (PFS), objective response rate (ORR), and primary tumor shrinkage were assessed. PFS and ORR were assessed per independent radiology review committee using RECIST version 1.1. With minimum study follow-up of 4 yr for intent-to-treat patients, OS favored NIVO+IPI (n = 53) over sunitinib (n = 55; hazard ratio 0.63, 95% confidence interval 0.40-1.0) among patients without prior nephrectomy. ORR was higher (34% vs 15%; p = 0.0041) and median duration of response was longer with NIVO+IPI versus sunitinib (20.5 vs 14.1 mo); the best overall response was partial response in either arm. A ≥30% reduction in the diameter of intact target renal tumors was achieved in 35% of patients with NIVO+IPI versus 20% with sunitinib. Safety was consistent with the global study population. In conclusion, in patients with aRCC without prior nephrectomy and with an evaluable primary tumor, NIVO+IPI showed survival benefits and renal tumor reduction versus sunitinib. This trial is registered at ClinicalTrials.gov as NCT02231749. PATIENT SUMMARY: In an exploratory analysis of a large global trial (CheckMate 214), we observed positive outcomes (both survival and tumor response to treatment) with nivolumab plus ipilimumab over sunitinib in a subgroup of patients with advanced kidney cancer who did not undergo removal of their primary kidney tumor. This subset of patients represents a population that has not been studied in clinical trials and for whom outcomes with new immunotherapy combination regimens are not yet known. We conclude that treatment with nivolumab plus ipilimumab offers these patients a survival benefit versus sunitinib, consistent with that observed in the overall study, as well as a notable kidney tumor reduction.

Temporal trends of adverse events and costs of nivolumab plus ipilimumab versus sunitinib in advanced renal cell carcinoma

Aims: To assess grade 3/4 adverse events (AEs) and costs of first-line nivolumab plus ipilimumab (NIVO + IPI) versus sunitinib in advanced or metastatic renal cell carcinoma. Methods: Individual patient data from the all treated population in the CheckMate 214 trial (NIVO + IPI, n = 547; sunitinib, n = 535) were used to calculate the number of AEs. AE unit costs were obtained from US 2017 Healthcare Cost and Utilization Project and inflated to 2020 values. Results: The proportion of patients experiencing grade 3/4 AEs decreased over time. Patients who received NIVO + IPI had lower average per-patient all-cause grade 3/4 AE costs versus sunitinib (12-month: US$15,170 vs US$20,342; 42-month: US$19,096 vs US$27,473). Conclusion: Treatment with NIVO + IPI was associated with lower grade 3/4 AE costs than sunitinib.

Efficacy of Nivolumab plus Ipilimumab According to Number of IMDC Risk Factors in CheckMate 214

In the randomized, open-label, phase 3 CheckMate 214 trial, nivolumab plus ipilimumab (nivolumab 3 mg/kg plus ipilimumab 1 mg/kg every 3 wk for four doses, then nivolumab 3 mg/kg every 2 wk) had superior efficacy over sunitinib (50 mg once daily, 4 wk on, 2 wk off) in patients with untreated International Metastatic Renal Cell Carcinoma Database Consortium (IMDC) intermediate- or poor-risk advanced renal cell carcinoma; the benefits were sustained through extended follow-up. To better characterize the association between outcomes and IMDC risk in CheckMate 214, we completed a post hoc analysis (n = 1051) of efficacy by the number of IMDC risk factors. The investigator-assessed objective response rate (ORR), overall survival (OS), and investigator-assessed progression-free survival (PFS) according to Response Evaluation Criteria in Solid Tumors v1.1 were evaluated. ORR with nivolumab plus ipilimumab was consistent across zero to six IMDC risk factors, whereas with sunitinib it decreased with increasing number of risk factors. Benefits of nivolumab plus ipilimumab over sunitinib in terms of ORR (40-44% vs 16-38%), OS (hazard ratio [HR] 0.50-0.72), and PFS (HR 0.44-0.86) were consistently observed in subgroups with one, two, three, or four to six IMDC risk factors (p < 0.05 for treatment × no. of risk factors interaction). These results demonstrate the benefit of first-line nivolumab plus ipilimumab over sunitinib across all intermediate-risk and poor-risk groups, regardless of the number of IMDC risk factors. PATIENT SUMMARY: This report from the CheckMate 214 study describes a consistent efficacy benefit with first-line nivolumab plus ipilimumab over first-line sunitinib in all groups of patients with intermediate-risk or poor-risk advanced renal cell carcinoma, regardless of the number of risk factors they had before starting treatment. We conclude that there is a benefit of first-line treatment with nivolumab plus ipilimumab for all intermediate-risk patients, including those with one or two risk factors, and for all poor-risk patients, independent of the number of risk factors.

Advances in the Treatment of Metastatic Renal Cell Carcinoma

The treatment landscape for metastatic renal cell carcinoma has constantly been in flux. In 2005, with the advent of vascular endothelial growth factor (VEGF) tyrosine kinase inhibitor (TKI) therapy, the standard of care shifted to agents such as sunitinib and pazopanib. However, more recently there have been datasets, suggesting that next-generation TKIs such as cabozantinib may play an important role in therapy. Furthermore, immunotherapy has had resurgence with the FDA approval of nivolumab with ipilimumab. In the current chapter, we attempt to contextualize available frontline therapies for metastatic renal cell carcinoma with a focus on the CABOSUN and CheckMate 214 clinical trials.