Imexon for Relapsed Follicular and Aggressive Lymphomas

Inclusion Criteria: 1. Diagnosis: Group 1: Histologically confirmed indolent NHL, including follicular (any grade), small lymphocytic lymphoma, marginal zone lymphoma and lymphoplasmacytic lymphomaGroup 2: histologically confirmed diffuse large B-cell, mantle cell, Burkitt, Burkitt-like, and diffuse large B-cell transformed from indolent non-Hodgkin's lymphoma. 2. Prior treatment: Group 1: (indolent histologies): Patients must have demonstrated relapsed or refractory disease to 1 prior treatment regimen. The maximum number of prior regimens used for treatment is not specified. Group 2: (aggressive histologies): Patients must have demonstrated relapsed or refractory disease to at least 1 prior treatment regimen. In the case of de novo diffuse large B-cell lymphoma, prior treatment must include R-CHOP or R-CHOP-like therapy, as well as second line autologous stem cell transplantation unless the patient is not eligible. The maximum number of prior regimens is not specified. 3. At least one target lesion, measurable by radiographic methods according to the 2007 Revised Response Criteria for Malignant Lymphoma. 4. ECOG Performance Status 0-2. 5. No clinical or laboratory evidence of central nervous system disease. 6. Adult (age 18 years or older). 7. Projected life expectancy \>4 months. 8. If female, neither pregnant (negative pregnancy test required at screening) nor lactating. 9. If of child-bearing potential, must be able to use and agree to use medically acceptable contraception for the duration of the study. For female subjects who are neither post-menopausal nor surgically sterilized, this includes oral or injectable hormonal methods, barrier methods such as an intra-uterine device, diaphragm with spermicide, condom with spermicide, or abstinence. Male subjects must also agree to use an acceptable method for contraception for the duration of the study. 10. No major infection or serious uncontrolled concomitant disease. Fully recovered from any major surgery. 11. No evidence of other concurrent active malignancy. 12. At least 4 weeks since any prior cancer chemotherapy (2 weeks for corticosteroids), antibody therapy, or radiotherapy. 13. Prior radiotherapy to less than an estimated 25% of the bone marrow. In addition, the target lesion(s) must not have been previously irradiated. 14. Clinical laboratory values within the following limits: 1. Hgb \>/=10.0 g/dL 2. Absolute neutrophil count ANC \>/=1,500/mm3 3. Platelets \>/=75,000/mm3 4. Serum creatinine \</=2.0 times upper limit of normal 5. Serum bilirubin \</=2.0 times upper limit of normal 6. Serum AST and ALT \</=3 times upper limit of normal 15. G6PD level \>/= lower limit of normal 16. Able and willing to render informed consent and to follow protocol requirements. Exclusion Criteria: 1. Diagnosis of lymphoma based on fine needle aspirate. 2. Curative therapy is indicated or possible. 3. Absence of a measurable target lesion, or the only target lesion was previously irradiated. 4. Symptoms, exam findings, or laboratory findings to suggest central nervous system disease involvement. 5. Age \< 18 years 6. Projected life expectancy \<4 months. 7. Pregnant or lactating. 8. Unable or unwilling to use medically acceptable contraception, if of childbearing potential. 9. Evidence of major infection or other serious uncontrolled concomitant illness. Not fully recovered from prior major surgery. 10. Evidence of other active malignancy. 11. Prior radiotherapy, antibody therapy, or cancer chemotherapy within 4 weeks before start of treatment (2 weeks for corticosteroids). Prior radiotherapy to \>25% of the bone marrow. 12. Clinical laboratory values outside of permitted ranges. 13. Respiratory insufficiency requiring oxygen therapy; angina at rest, or myocardial infarction in previous 3 months; history of life threatening ventricular arrhythmia; uncompensated CHF or NYHA Grade 3 or 4 cardiac disease. 14. Unable or unwilling to give informed consent and to follow protocol requirements. 15. Failure to meet any of the eligibility criteria.