Study of the Safety of GCS-100 in Subjects With Chronic Lymphocytic Leukemia

Inclusion Criteria: Eligible subjects must meet all of the following criteria: 1. Subject is capable of understanding the purpose and risks of the study and is able to provide written Informed Consent. 2. Subject is male or female, aged at least 18 years. 3. Subject has been diagnosed with chronic lymphocytic leukemia. 4. Subject has Stage II or higher, chronic lymphocytic leukemia that currently requires therapy due to the severity of the disease symptoms and/or to the presence of increasing anemia and/or increasing splenomegaly. 5. Subject has received 2 or fewer prior therapies for his/her chronic lymphocytic leukemia. 6. Subject does not currently require blood transfusions. 7. Subject's peripheral blood leukocyte count is \> 10,000 cells/mm3. 8. Subject's Karnofsky performance status is \> 60%. 9. Subject's life expectancy is at least 3 months. 10. Female subjects of childbearing potential (i.e., women who have not been surgically sterilized or have not been post-menopausal for at least 1 year), and male subjects with partners of childbearing potential, must agree to use medically acceptable methods of contraception throughout the entire study period. 11. Subject is willing and able to comply with the prescribed treatment protocol and evaluations. Exclusion Criteria: Subjects will be ineligible for study participation if they meet any of the following criteria: 1. Subject received biologic therapy and/or chemotherapy that may be active against chronic lymphocytic leukemia within the 4 weeks prior to Study Day 1. 2. Subject is anticipated to require steroid therapy within the next 21 days. 3. Subject received an investigational (i.e., experimental) therapy within the 4 weeks prior to Study Day 1. 4. Subject's clinical laboratory values meet any of the following criteria within the 7 days prior to Study Day 1: * Platelet count \< 25,000 cells/mm3 * Absolute neutrophil count \< 500 cells/mm3 * Hemoglobin \< 8.0 g/dL and with an autoimmune hemolytic component to the subject's anemia * AST and/or ALT \> 2.5 X the upper limit of normal * Total bilirubin \> 1.5 X the upper limit of normal * Serum creatinine \> 2 mg/dL 5. Subject has a known history of human immunodeficiency virus (HIV), hepatitis B, and/or hepatitis C infection. 6. Subject has a clinically relevant active infection and/or a serious co-morbid medical condition, such as recent myocardial infarction, unstable angina, difficult-to-control congestive heart failure, uncontrolled hypertension, difficult-to-control cardiac arrhythmias, chronic obstructive or chronic restrictive pulmonary disease, cirrhosis, inflammatory bowel disease. 7. Subject had major surgery within the 4 weeks prior to Study Day 1. 8. Subject had another malignancy within the 3 years prior to study entry, with the exception of adequately treated basal cell or squamous cell skin cancer, in situ cervical cancer, in situ breast cancer, in situ prostate cancer, or other cancer for which the subject has been disease-free for at least 3 years. 9. If female, subject is pregnant or breast-feeding. 10. Subject has a concomitant disease or condition, including laboratory abnormalities, which in the opinion of the Investigator could interfere with the conduct of the study or could put the subject at unacceptable risk.