Treatment patterns: Targeted therapies indicated for first-line management of metastatic renal cell carcinoma in a real-world setting.

416 Background: Limited information about real-world treatment patterns of targeted agents for metastatic renal cell carcinoma (mRCC) is available to inform their use in clinical practice. Methods: This retrospective, observational study employed US claims data (January 2007-November 2010) to identify treatment patterns, including treatment duration and dosing, for targeted agents (sunitinib, sorafenib, pazopanib, bevacizumab, and temsirolimus) indicated in 1st line management of advanced/mRCC. The study included adult mRCC patients who were observed for ≥3 months after initiation of their 1st line therapy with a targeted agent. Descriptive analyses were conducted for the observed treatment patterns. Results: A total of 273 patients on 1st line therapy were identified and included in the study sample out of which 235 patients were treated with sunitinib, 16 patients with sorafenib, and 15 patients with temsirolimus. Pazopanib and bevacizumab were excluded from further analysis due to their small samples; n<10. The median observed treatment durations were: sunitinib 3.3 months, sorafenib 4.0 months, and temsirolimus 2.6 months. Patients initiating therapy on sorafenib (n=16) and temsirolimus (n=15) in the study sample were insufficient for meaningful dosing analyses. In sum, of the n=235 sunitinib patients, 178 (approximately 76%) initiated therapy at the indicated dose of 50 mg. Sixty-five percent of these patients were not observed filling a 4th script (the average number observed), while 26% maintained their starting dose and 9% experienced a dose reduction at their fourth fill. (See table). Conclusions: This study suggests that opportunities exist to improve treatment duration in real-world clinical practice and to better understand possible influences, other than disease progression, on treatment and dose changes. [Table: see text]