Quality-adjusted Time Without Symptoms or Toxicity (Q-TWiST) for Lenvatinib plus Everolimus Versus Everolimus Monotherapy in Patients with Advanced Renal Cell Carcinoma

BACKGROUND: The lenvatinib (LEN) plus everolimus (EVE) combination demonstrated improved progression-free survival over everolimus alone in a phase 2 trial (Study-205). OBJECTIVE: To compare quality-adjusted time without symptoms of disease progression or toxicity (Q-TWiST) between LEN + EVE and EVE alone among patients with advanced renal cell carcinoma (RCC) following one prior antiangiogenic therapy. DESIGN, SETTING, AND PARTICIPANTS: This was a post hoc analysis of Study-205. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Survival time was partitioned into three mutually exclusive health states: time with grade 3/4 toxicity (TOX); time before disease progression and without grade 3/4 toxicity (TWiST); and time after disease progression (REL). The mean time in each state was weighted by utility measures and summed to calculate Q-TWiST. Nonparametric bootstrapping generated 95% confidence intervals (CIs). In the base case, utility for TWiST, TOX, and REL was assigned as 1.0, 0.5, and 0.5, respectively. Sensitivity analyses applied alternative utility values for REL, TOX, and TWiST. A relative gain in Q-TWiST of ≥10% and ≥15% has been established as clinically important and clearly clinically important, respectively. RESULTS AND LIMITATIONS: Patients receiving LEN + EVE (n = 51) had a significant mean Q-TWiST gain of 3.7 mo (14.7 vs 11.0 mo; 95% CI for difference 1.3–6.3), with a relative gain of 24% compared to EVE alone. In a sensitivity analysis using alternative utility values for TWiST (varied from 0.55 to 0.9) with utility set to 0.5 for both TOX and REL, the relative Q-TWiST gain was maintained (ranging from 11.0% to 21.2%; all significant) across varying utility values. Limitations include the sample size, the absence of utility estimates, and the length of adverse events from the trial. CONCLUSIONS: LEN + EVE showed a significant and clearly clinically important improvement in quality-adjusted survival time versus EVE alone. PATIENT SUMMARY: Patients with advanced kidney cancer who had received other previous treatments experienced a clearly clinically important improvement in quality survival time when treated with lenvatinib plus everolimus compared to everolimus alone.