Study of Weekly Motexafin Gadolinium (MGd) for Patients With Chronic Lymphocytic Leukemia or Small Lymphocytic Lymphoma

* ≥ 18 years old * CLL as defined by the NCI 96 criteria (exception; patients may have bright surface immunoglobulin staining if negative for t\[11;14\] translocation or cyclin D1) or SLL as defined by WHO classification criteria and is refractory or relapsed as defined by one of the following: * Refractory disease: progressive disease while on therapy * Relapsed disease: progressive disease after at least one treatment course of therapy with disease response or stabilization * ECOG performance status score of 0, 1, or 2 * Willing and able to provide written informed consent

* Laboratory values of: * Platelet count \< 30,000/µL * AST or ALT \> 2 x ULN (upper limit of normal) * Total bilirubin \> 2 x ULN * Creatinine \> 2 mg/dL * Chemotherapy, radiation therapy, immunotherapy, systemic corticosteroids (\> 10 mg oral prednisone or equivalent), or systemic biologic anticancer therapy within 21 days before beginning study treatment * Major surgery or hospitalization for a serious illness within the last 3 months * Greater than three prior regimens (where a regimen is defined as a treatment for CLL/SLL given initially or after disease progression) * Prior malignancy requiring current or prior treatment within the past 5 years, except for cervical neoplasia in situ and non-melanomatous skin cancer * Uncontrolled hypertension