Efficacy and Safety of Sunitinib (su) in Patients (pts) with Metastatic Renal Cell Carcinoma (mrcc) and Lung Metastases (mets) Only at Baseline

e15098 Background: The lungs may be the sole site of mets in RCC.In this retrospective analysis, we analyzed the efficacy and safety of SU in mRCC pts from a global phase (ph) III study and a Japanese ph II study who had lung mets only at baseline. Methods: In the ph III study, treatment (Tx)-naïve mRCC pts were randomized 1:1 to SU 50 mg/d on a 4-weeks-on-2-weeks-off schedule (n=375) or interferon-a (IFN) 9 MU subcutaneously TIW (n=360). In the single-arm ph II study, Tx-naïve (n=25) and cytokine refractory (n=26) mRCC pts received the same SU Tx. In the ph III study, progression-free survival (PFS) and overall survival (OS) were estimated by Kaplan–Meier method, with median values compared by log-rank test. In both studies, objective response rate (ORR) was calculated with a two-sided 95% CI. PFS, OS, ORR, and safety were analyzed at final data cutoff. Results: In the ph III study, 31 (8%) and 42 (11%) pts in the SU and IFN groups, respectively, had lung mets only, compared with 12 (24%) in the ph II study. Baseline characteristics in lung mets pts were similar to all pts. In lung mets pts from the ph III study, ORR was higher with SU than with IFN (58.1% [95% CI: 39.1–75.5] vs. 19.0% [95% CI: 8.6–34.1]; P<0.001); there was a trend for longer median PFS with SU (14.1 vs. 7.8 months; HR: 0.531 [95% CI: 0.278–1.015]; P=0.0513); and median OS was comparable in both Tx subgroups (HR: 0.739 [95% CI: 0.335–1.628]; P=0.4507), although, at 25% of events, median OS was 22.9 months with SU vs. 15.8 months with IFN. In lung mets pts from the ph II study, ORR was 75.0% (95% CI: 42.8–94.5); at the time of analysis, median PFS and OS had not been reached; 4 pts (33%) had died due to any cause and 8 (67%) were alive without disease progression. The most common grade ≥3 SU-related AEs were fatigue, hand-foot syndrome, and diarrhea (all 19%) in the ph III study, and decreased platelets (100%), white blood cells (92%), and neutrophils (92%) in the ph II study. Conclusions: In the ph III study, Tx-naïve mRCC pts with lung mets only had significantly higher ORR and a trend for improved PFS and OS with SU compared with IFN. In the Japanese ph II study, ORR with SU was 75% in lung mets pts. Thus, 1st-line use of SU in mRCC pts with lung mets should be encouraged.