Background: The Memorial Sloan Kettering Cancer Center risk model (MSKCC) stratifies pts with mRCC into 3 prognostic groups based on 5 risk factors. The Intermediate Prognosis (INTMP) risk group is characterized by the presence of 1 or 2 factors, equivalent to 15 possible distinct entities. This heterogeneity suggests that the efficacy of tyrosine kinase inhibitors may be less predictable in the INTMP than in the other groups. Methods: We identified 548 patients with INTMP mRCC from a pooled analysis of patients treated with sunitinib in 6 prospective phase II and III clinical trials. Statistical analysis was performed using Cox regression and Kaplan-Meier methods and Pearson chi-square tests. Results: Most INTMP pts were male (69%), with clear cell carcinoma (93%), good ECOG performance status (PS) (60.5% PS 0; 38% PS 1; 1.5% PS 2) and median age 60. There were 325 pts (56%) with 1risk factor, and the most common were <1 year from diagnosis (38%); low hemoglobin (Hg) (29%), or both (16%). Objective response rate (RR) was 35.4%, progression free survival (PFS) was 8.4 months (m) and overall survival (OS) was 20.5 m. The 325 (59.3%) pts with one risk factor fared better than the 223 (40.7%) patients with two: PFS 10.7 vs 6.5 m, HR 0.684(95% CI 0.563-0.832, p<0.001); OS 26.3 vs 14.1 m, HR 0.522 (95% CI 0.420-0.648, p<0.001). RR was similar (38.5% vs 30.9%, p=0.071). Sunitinib was more effective in pts with PS 0: PFS 9.7 vs 7.8 m, HR 0.797 (95% CI 0.654-0.972, p=0.0242); OS 24.7 vs 14.0 m, HR 0.529 (95% CI 0.426-0.657, p<0.001), RR 38.9% vs 30.1%, (p=0.036). The most common grade 3/4 adverse events (AE) were fatigue (17%), hypertension (10%), hand foot skin reaction (9%), and nausea (4%). Overall, 17% of patients discontinued due to AE, and the overall pattern of AEs did not vary among the subgroups. Conclusions: MSKCC INTMP is a heterogeneous group comprised mostly of pts with low Hg and/or < 1 year from diagnosis. PFS and OS are superior in pts with 1 vs. 2 risk factors, and PS is also an important factor in the INTMP group. Sunitinib is active and well-tolerated in INTMP pts. Clinical trial information: NCT00077974, NCT00083889, NCT00137423, NCT00267748, NCT00338884, NCT00054886.