Quality-adjusted time without symptoms of disease progression or toxicity (Q-TWiST) of nivolumab plus cabozantinib (N+C) versus sunitinib (SUN) in treatment-naïve, advanced/metastatic renal cell carcinoma (aRCC): A post-hoc analysis of CheckMate 9ER (CM 9ER) data.
Authors: Cella David , Motzer Robert J. , May Jessica , Wallace Joel , Marteau Florence , Kwon Youngmin , Rusibamayila Nifasha , Botteman Marc , Ejzykowicz Flavia , Choueiri Toni K. 
Published: June 2021

6567 Background: In CM 9ER (ClinicalTrial.gov identifier NCT03141177), N+C demonstrated significant progression-free survival gains (median: 17.0 vs. 8.3 months [mos]; hazard ratio [HR]: 0.52; P <.0001) and overall survival (OS) benefits (median: not reached vs. 29.5 mos; HR: 0.66; P <.001) vs. SUN as a first-line treatment for aRCC (Motzer et al. ASCO-GU 2021). To more fully understand the clinical benefits and risks associated with N+C vs. SUN from a patient perspective, we applied the Q-TWiST method to CM 9ER data to assess the quality-adjusted survival of these two treatment options, after a minimum follow-up of 16 mos (Sept DBL 2020). Methods: OS was partitioned into 3 states: time with any grade 3 or 4 adverse events (TOX), time without symptoms of disease or toxicity (TWiST), and time after progression (REL). The Q-TWiST is a metric that combines the quantity and quality (i.e., “utility”) of time spent in each of the 3 states TWiST, TOX, and REL. Sensitivity analyses estimated Q-TWiST across varying values of TOX and REL utilities. Subgroup analyses were conducted based on geographic region, programmed cell death-ligand 1 status, and International Metastatic RCC Database Consortium risk score. Based on minimal important difference norms (Revicki et al, Qual Life Res, 2006), a relative gain in Q-TWiST (i.e., Q-TWiST gains divided by OS in SUN) of ≥ 10% and ≥ 15% were qualified as “clinically important” and “clearly clinically important” gains, respectively. Non-parametric bootstrapping was used to generate 95% confidence intervals (CI). Results: In the intent-to-treat (ITT) population (N = 651), the Q-TWiST gain in the N+C arm was 4.0 mos (95% CI: 2.4, 5.7) vs. SUN arm, resulting in a relative gain of 16.9%. N+C patients had significantly longer TWiST (4.7 mos [95% CI: 2.9, 6.7]) and TOX (0.5 mos [95% CI: 0.1, 0.9]), but significantly shorter REL (-2.0 mos [95% CI: -4.1, -0.1]) than did SUN patients. Sensitivity analyses were consistent with the main analysis—the Q-TWiST benefit was robust across different ranges of U(TOX) and U(REL), with minimum and maximum Q-TWiST gains of 2.7 mos (11.7% relative gain) and 5.2 mos (22.2% relative gain), respectively. Subgroup analyses were consistent with the ITT population, with all results demonstrating ≥10% (“clinically important”) gains favoring N+C. Conclusions: In CM 9ER, N+C resulted in a statistically significant and “clearly clinically important” (i.e., ≥ 15%) longer quality-adjusted survival vs SUN. Most gains were driven by added time in relatively good health (i.e., TWiST). These Q-TWiST results may help inform both aRCC patients and their clinicians to assess more comprehensively the clinical benefits and risks of N+C and SUN in making critical treatment decisions. Clinical trial information: NCT03141177.