Quality of life (QOL) with sunitinib versus interferon-alfa (IFN-α) as first-line therapy in patients with metastatic renal cell carcinoma (mRCC): Final results

Abstract

6529 Background: In an international, randomized phase 3 trial (Figlin et al, ASCO. 2008), sunitinib showed superior progression-free survival (the primary endpoint) and objective response rate over IFN-α (11 vs. 5 mo and 47% vs. 12%, respectively; p < 0.000001) as first-line mRCC therapy, with a median overall survival of more than 2 years. Here, we report the final health-related QOL results from this trial. Methods: 750 treatment-naïve mRCC patients were randomized 1:1 to receive sunitinib 50 mg orally once-daily in recurring cycles of 4 weeks on drug and 2 weeks off or IFN-α 9 MU subcutaneously thrice-weekly. QOL was measured by the Functional Assessment of Cancer Therapy-General (FACT-G), which has 4 subscales, the FACT-Kidney Symptom Index-15 item (FKSI-15), which includes a Disease-Related Symptoms (FKSI-DRS) subscale, and the EQ-5D questionnaire's utility index (EQ-5D Index) and visual analog scale (EQ-VAS). The primary QOL endpoint was FKSI-DRS. Higher scores indicated better outcomes. Patients completed questionnaires on days 1 and 28 of each cycle. Data were analyzed for the intent-to-treat population using mixed-effects models (MM), supplemented with pattern-mixture models (PMM). We also compared QOL of patients in the United States (US) with patients in the European Union (EU; France, Germany, Italy, Poland, Spain and United Kingdom). Results: Patients on sunitinib reported better FKSI-15 and FKSI-DRS scores than those on IFN-α, with a significant difference in the overall means across cycles (4.06 and 2.36, respectively; p < 0.0001; MM). Similarly, differences in means for FACT-G (and all subscales), EQ-5D Index, and EQ-VAS all significantly favored sunitinib (p < 0.05). Based on pre-set, required minimum score differences, between-treatment differences in the mean scores were clinically meaningful for FKSI-15, FKSI-DRS, FACT-G, and the FACT-G functional well-being subscale. Between-treatment differences were similar for both the US and EU populations. Across all analyses, results from PMM were similar to those from MM. Conclusions: Sunitinib provides superior QOL over IFN-α, in addition to superior efficacy, as first-line mRCC therapy. [Table: see text]