The purpose of this study is to confirm the efficacy and safety of fludarabine phosphate administered with dose increasing in 6 cycles (1 cycle: 5 treatment days every 28 days) in untreated chronic lymphocytic leukemia (CLL) patients with anemia and/or thrombocytopenia.

As of 29 May 2009, the clinical trial sponsor is Genzyme Corporation. NOTE: This study was originally posted by sponsor Schering AG, Germany, which was subsequently renamed to Bayer Schering Pharma AG, Germany.

Inclusion Criteria:

• Patients with histologically or cytologically confirmed CLL
• Patients with hemoglobin concentration and/or platelet count below the institution's lower limit of normal
• Patients who have not received cancer chemotherapy or radiotherapy

Exclusion Criteria:

• Patients with apparent infections (including viral infections)
• Patients with serious complications (heart, liver, or kidney disease, etc.)
• Patients with a serious bleeding tendency (e.g., DIC)
• Patients with serious CNS symptoms
• Patients with fever >= 38°C (excluding tumor fever)
• Patients with interstitial pneumonia or pulmonary fibrosis
• Patients with active multiple cancers
• Patients receiving other investigational products within 6 months before registration in this study
• Patients with prior allergies to medications that are similar to the investigational product (purine nucleoside derivatives)
• Women who are pregnant, of childbearing potential, or lactating