Post hoc analysis of the CLEAR study in advanced renal cell carcinoma (RCC): Effect of subsequent therapy on survival outcomes in the lenvatinib (LEN) + everolimus (EVE) versus sunitinib (SUN) treatment arms.
Authors: Hutson Thomas E. , Choueiri Toni K. , Motzer Robert J. , Rha Sun Young , Alyasova Anna , Merchan Jaime R. , Gurney Howard , Peer Avivit , Takagi Toshio , Porta Camillo , Powles Thomas , Grünwald Viktor , De Giorgi Ugo , Vaishampayan Ulka N. , Schmidinger Manuela , Glen Hilary , Rodriguez-Lopez Karla , Xing Dongyuan , Dutta Lea , Eto Masatoshi 
Published: June 2021

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Background: The multicenter, open-label, randomized, phase 3 CLEAR study showed that LEN + EVE had a significant PFS benefit (HR 0.65, 95% CI 0.53-0.80, P<0.001) and improved objective response rate (relative risk 1.48, 95% CI 1.26-1.74) vs SUN in the first-line treatment of patients (pts) with advanced RCC. The difference in overall survival (OS) for LEN + EVE vs SUN was not statistically significant (HR 1.15, 95% CI 0.88-1.50) (Motzer R et al. NEJM. 2021). Post hoc subgroup analyses were performed to assess the impact of subsequent therapy on OS. Methods: Pts in the CLEAR study were randomly assigned (1:1:1) to 1 of 3 treatment arms, including LEN 18 mg + EVE 5 mg once daily (QD) and SUN 50 mg QD (4 weeks on then 2 weeks off). These post hoc analyses examined OS by subsequent systemic anticancer medication in the LEN + EVE and SUN arms. Hazard ratios (HR; LEN + EVE vs SUN) were based on stratified (geographic region and MSKCC prognostic risk groups) Cox proportional hazards model. Results: Among 1069 pts with advanced RCC randomized in the CLEAR study, 714 pts were randomly assigned to the LEN + EVE and SUN arms (N=357/each). The median duration of survival follow-up was 27 months in the LEN + EVE arm and 26 months in the SUN arm. Given the shorter median duration of study treatment with SUN (7.8 months) vs LEN + EVE (11.0 months), more pts in the SUN arm received subsequent anticancer therapy during survival follow-up (LEN + EVE, n=167; SUN, n=206). Among pts who received subsequent therapy, pts in the LEN + EVE arm had a longer median time from randomization to initiation of subsequent therapy vs those in the SUN arm (8.0 vs 6.6 months, respectively). OS for the overall population, for pts with no subsequent anticancer therapy, and for pts with no subsequent immunotherapy is shown in the table. In the US population subgroup (LEN + EVE, n=62; SUN, n=61) of the CLEAR study, in which a similar number of pts received subsequent systemic anticancer therapies in the LEN + EVE vs SUN arms (62.9% vs 65.6%, respectively), OS was comparable among the 2 arms (HR 0.95, 95% CI 0.51-1.76). Overall, the safety profile was consistent with the known safety profiles of LEN + EVE and SUN. In both arms, most treatment-emergent deaths were due to progressive disease; there were few treatment-related deaths (<1%, per arm) and no clustering of events. Conclusions: In the CLEAR study, LEN + EVE met the primary endpoint of a significant benefit in PFS vs SUN. The results of these exploratory analyses suggest that subsequent systemic anticancer therapy affected the OS outcome results for LEN + EVE vs SUN in the CLEAR study. Clinical trial information: NCT02811861. [Table: see text]