8 Nivolumab plus ipilimumab vs sunitinib for first-line treatment of advanced renal cell carcinoma: 8-year follow-up with analyses in favorable risk patients from the phase 3 CheckMate 214 trial

Abstract

Background

First-line nivolumab plus ipilimumab (NIVO+IPI) has provided substantial long-term survival benefits over sunitinib (SUN) in patients with advanced renal cell carcinoma (aRCC) in CheckMate 214. With a median follow-up of 8 years, the longest follow-up to date for any phase 3 trial of immune checkpoint inhibitor combination therapy in patients with aRCC, we report survival, response per independent radiology review committee (IRRC), and safety in all randomized patients (intent-to-treat [ITT] population) and in patients with International Metastatic Renal Cell Carcinoma Database Consortium (IMDC) favorable risk.

Methods

Patients with clear cell aRCC were randomized 1:1 to NIVO 3 mg/kg plus IPI 1 mg/kg Q3W×4 doses, followed by NIVO (3 mg/kg or 240 mg Q2W or 480 mg Q4W); or SUN 50 mg once daily for 4 weeks on, 2 weeks off. Key study endpoints included overall survival (OS), IRRC-assessed progression-free survival (PFS) and objective response rate (ORR) in intermediate/poor-risk (primary), ITT (secondary), and favorable-risk (exploratory) patients. Cancer-specific survival was evaluated in ITT patients by censoring all causes of death other than RCC. Post hoc exploratory analyses in patients with favorable risk were performed.

Results

With 8 years (99.1 months) median follow-up, OS with NIVO+IPI versus SUN remained superior in ITT patients (hazard ratio [HR], 0.72; Table). The HR for PFS with NIVO+IPI versus SUN was 0.88. ORR was higher with NIVO+IPI versus SUN (Table), with more complete responses (12% vs 3%) and a longer median duration of response (DOR) in the combination arm versus SUN. In patients with favorable risk, OS benefits were similar between arms (HR, 0.82; Table). The HR for PFS favored SUN (HR, 1.76). ORR was lower with NIVO+IPI versus SUN, yet more patients achieved complete responses (13% vs 6%, respectively) and median DOR was longer with NIVO+IPI. Median cancer-specific survival (95% CI) in ITT patients was 73.7 (62.8-91.2) months with NIVO+IPI versus 45.1 (37.8-53.3) months with SUN (HR, 0.69; 95% CI 0.59-0.82). In exploratory post hoc analyses of patients with favorable risk, 75/125 (60.0%) patients in the NIVO+IPI arm and 85/124 (68.5%) patients in the SUN arm died over 8 years of follow-up. Of these patients, 31 in the NIVO+IPI arm and 27 in the SUN arm died within 3 years of randomization; the primary reason for death was disease in either arm (71.0% and 85.2%, respectively). Furthermore, among 27 patients in the NIVO+IPI arm with favorable risk who died after disease progression within 3 years, 12 patients did not receive second-line systemic therapy. Beyond 3 years, only 2 of 43 patients who died after disease progression did not receive subsequent systemic therapy. Among all treated patients, incidence of any-grade and grade 3-4 treatment-related adverse events remained largely unchanged. No new drug-related deaths occurred in either arm since the previous database lock.

Table

	ITT		Favorable risk
Arm; n	NIVO+IPI (N=550)	SUN (N=546)	NIVO+IPI (N=125)	SUN (N=124)
OS HR (95% CI)	0.72 (0.62-0.83)		0.82 (0.60-1.13)
mOS (95% CI), months	53 (46-65)	38 (32-44)	78 (65-92)	67 (56-80)
PFS per IRRC, HR (95% CI)	0.88 (0.75-1.03)		1.76 (1.25-2.48)
mPFS (95% CI), months	12 (10-17)	12 (10-15)	12 (10-18)	29 (23-43)
ORR per IRRC (95% CI), %	39 (35-44)	33 (29-37)	30 (22-38)	52 (43-61)
Complete response per IRRC, %	12	3	13	6
DOR HR (95% CI)	0.52 (0.38-0.72)		0.70 (0.36-1.34)
mDOR (95% CI), months	76 (59-NE)	25 (20-33)	61 (28-NE)	33 (25-51)

m, median; NE, not estimable.

Conclusions

With a median follow-up up of 8 years, NIVO+IPI continues to demonstrate sustained survival and more durable response benefits versus SUN in the ITT population, including a further reduction in the risk of death with NIVO+IPI as measured by cancer-specific survival. Long-term exploratory data in patients with favorable risk have shown a steady improvement in the HR for OS, and a marked improvement in median DOR and complete response rates with NIVO+IPI versus SUN, thus contributing to the survival and response benefits reported in the ITT population. Furthermore, the disproportionate number of patients with favorable risk who died within 3 years of randomization after documented progression without receiving subsequent therapy may have affected the HR for OS in this patient population early on. NIVO+IPI offers the potential for positive long-term outcomes, regardless of IMDC risk, and with no emergence of new safety signals.