Chronic lymphocytic leukemia (CLL) is the most common leukemia in the western world, accounting for approximately 30% of adult leukemias. The majority of CLL patients are elderly and have co-existing medical conditions. This limits therapeutic options and precludes many from receiving the recognized standard of care regimen, fludarabine, cyclophosphamide and rituximab (FCR). A number of recent studies have evaluated alternative chemoimmunotherapies for these patients. The objective of this study was to describe patient characteristics, treatment patterns, and resource utilization for patients who are unfit for a standard fludarabine-based regimen as first-line treatment for CLL in Spain, Italy, and the UK. A retrospective chart review was undertaken at 18 sites in Spain, 16 in Italy, and 17 in the UK, to identify CLL patients who initiated treatment between January 2011 and December 2012, with a target sample size of 150 per country. Eligible patients were defined as those who initiated first-line CLL treatment that did not include fludarabine (UK and Spain) or standard-dose fludarabine (Italy) which ensured that elderly patients with comorbidities were included. The variability in definitions was due to increased use of reduced-dose fludarabine regimens in Italy for patients not otherwise suitable for a standard dose of fludarabine. Data on demographic and disease-related characteristics, treatment patterns, and health resource utilization were abstracted from diagnosis until December 2013. Among eligible patients (Spain, n=127, Italy, n=121, UK, n=94), the mean age at treatment initiation was 75.9, 73.8, and 76.8 years, respectively. In the UK, 89.4% had 2 or more comorbidities compared to 74.8% in Spain and 65.3% in Italy. In all countries, chlorambucil monotherapy was the single most common regimen, prescribed to 59.6% of patients in the UK, 38.6% in Spain, and 30.6% in Italy. Bendamustine plus rituximab was the next most common regimen in the UK (17.0%) and Italy (23.1%). In Spain, the second-most common regimen was chlorambucil plus rituximab (18.9%). In Italy, 9.9% of patients received the reduced-dose fludarabine regimen, FCR-Lite. In both Spain and the UK, 40% of patients were hospitalized during the follow-up period, compared to 27% in Italy. Emergency room use ranged from 2% in the UK to 40% in Spain. A large majority of patients in all countries utilized outpatient services and laboratory monitoring, with more frequent of visits in Spain and Italy relative to the UK. Hospitalization costs were the largest cost driver (3284 in Spain, 1312 in Italy, 10291 in the UK). Observed differences in hospital costs across countries were due to variation in: the proportion of individuals being hospitalized, with hospitalizations less common in Italy; length of hospital stay, with a minority of long and costly hospital stays in the UK; and hospital per diem costs. In Spain, outpatient visits comprised the second largest category of costs, while in Italy the second largest category was laboratory tests. In the UK, the second largest category was hospice care, although this was heavily influenced by a small number of individuals with very lengthy hospice stays. For the majority of UK patients, outpatient care was the second-highest category of costs. In conclusion, CLL patients who initiated first-line therapy during 2011 and 2012, with a regimen that did not include fludarabine (UK and Spain) or did not contain standard-dose fludarabine (Italy), were elderly, with 2 or more comorbidities. The most frequently administered treatment was chlorambucil monotherapy. Resource utilization patterns varied across countries; while some differences may have resulted from differences in patient and disease characteristics, they likely also reflect variation in management strategies between these countries. These results provide valuable baseline data to understand the potential impact of future treatments for this patient population. Abstract 2646. Table 1.SpainItalyUK% with utilizationMean annual cost per patient ()% with utilizationMean annual cost per patient ()% with utilizationMean annual cost per patient ()Hospitalization40.5328426.9131240.410291Hospice008.42055.36380Emergency room40.311515.01072.24Laboratory95.052899.052687.178Outpatient95.0116794.021968.8874Transfusions25.25117.04330.1226 Disclosures Delgado: Roche: Consultancy, Honoraria, Research Funding; Gilead: Consultancy, Research Funding, Speakers Bureau; GSK: Consultancy, Honoraria, Research Funding; Mundipharma: Consultancy, Honoraria; Celgene: Honoraria; Novartis: Consultancy, Honoraria. Rossi:Amgen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding. Raine:GSK: Employment. Haiderali:GSK: Employment.