Summary Background Results from clinical trials have established sunitinib as a standard of care for first-line treatment of advanced or metastatic renal-cell carcinoma (RCC); however, many patients, particularly those with a poorer prognosis, do not meet inclusion criteria and little is known about the activity of sunitinib in these subgroups. The primary objective of this trial was to provide sunitinib on a compassionate-use basis to trial-ineligible patients with RCC from countries where regulatory approval had not been granted. Methods Previously treated and treatment-naive patients at least 18 years of age with metastatic RCC were eligible. All patients received open-label sunitinib 50 mg orally once daily on schedule 4-2 (4 weeks on treatment, 2 weeks off). Safety was assessed regularly, tumour measurements done per local practice, and survival data collected where possible. Analyses were done in the modified intention-to-treat (ITT) population, which consisted of all patients who received at least one dose of sunitinib. This study is registered with ClinicalTrials.gov , NCT00130897. Findings As of December, 2007, 4564 patients were enrolled in 52 countries. 4371 patients were included in the modified ITT population. This population included 321 (7%) patients with brain metastases, 582 (13%) with Eastern Cooperative Oncology Group (ECOG) performance status of 2 or higher, 588 (13%) non-clear-cell RCC, and 1418 (32%) aged 65 years or more. Patients received a median of five treatment cycles (range 1–25). Reasons for discontinuation included lack of efficacy (n=1168 27%) and adverse events (n=362 8%). The most common treatment-related adverse events were diarrhoea (n=1936 44%) and fatigue (n=1606 37%). The most common grade 3–4 adverse events were fatigue (n=344 8%) and thrombocytopenia (n=338 8%) with incidences of grade 3–4 adverse events similar across subgroups. In 3464 evaluable patients, the objective response rate (ORR) was 17% (n=603), with subgroup ORR as follows: brain metastases (26 of 213 12%), ECOG performance status 2 or higher (29 of 319 9%), non-clear-cell RCC (48 of 437 11%) and age 65 years or more (176 of 1056 17%). Median progression-free survival was 10·9 months (95% CI 10·3–11·2) and overall survival was 18·4 months (17·4–19·2). Interpretation In a broad population of patients with metastatic RCC, the safety profile of sunitinib 50 mg once-daily (initial dose) on schedule 4-2 was manageable and efficacy results were encouraging, particularly in subgroups associated with poor prognosis who are not usually entered into clinical trials. Funding Pfizer Inc.