To determine the safety and efficacy of elsamitrucin in patients with relapsed or refractory non-Hodgkin's lymphoma (NHL). To determine if elsamitrucin is efficacious in a particular pathologic NHL subtype(s).

Inclusion Criteria:

• Relapsed or Refractory mantle cell lymphoma and/or CLL/SLL except Burkitt's, Burkitt's like or HIV-associated lymphoma
• at least one prior cytotoxic chemotherapy regimens
• measurable disease
• adequate bone marrow, liver and kidney function
• ECOG PS 0-2

Exclusion Criteria:

• prior treatment with elsamitrucin
• prior chemo, antibody or radiotherapy for NHL within 28 days prior to start to treatment
• HIV positive or known AIDS syndrome
• uncontrolled medical disease or psychiatric condition/s