Obatoclax Mesylate, Rituximab, and Bendamustine Hydrochloride in Treating Patients With Relapsed or Refractory Non-Hodgkin Lymphoma

Inclusion Criteria:

* Histologically confirmed indolent B-cell non-Hodgkin lymphoma (NHL), including any of the following subtypes recognized by WHO classification:

  * Marginal zone lymphoma
  * Lymphoplasmacytic lymphoma
  * Follicular lymphoma
  * Mantle cell lymphoma
* Transformed lymphoma from a low-grade, indolent NHL allowed provided patient has received ≥ 1 prior therapy for indolent disease
* Must have received ≥ 1 prior therapy
* Relapsed disease after autologous or allogeneic stem cell transplantation (SCT) allowed (phase I)

  * No relapse after allogeneic SCT (phase II)
* No known CNS lymphoma
* ECOG performance status 0-2
* ANC ≥ 1,000/µL
* Platelet count ≥ 50,000/µL
* Total bilirubin ≤ 1.5 times upper limit of normal (ULN)
* AST and ALT ≤ 2.5 times ULN
* Creatinine ≤ 2.0 mg/dL OR creatinine clearance ≥ 50 mL/min
* Not pregnant or nursing
* Fertile patients must use effective contraception prior to and for the duration of study participation
* No active hepatitis B infection

  * Patients with a history of hepatitis B (surface antigen or core antibody positive) must take lamivudine or equivalent during study therapy
* No history of documented human anti-globulin antibodies, or a history of allergic reactions attributed to compounds of similar chemical or biologic composition to rituximab, bendamustine hydrochloride, or obatoclax mesylate
* No uncontrolled intercurrent illness including, but not limited to, any of the following:

  * Ongoing or active infection
  * Symptomatic congestive heart failure
  * Unstable angina pectoris
  * Cardiac arrhythmia
  * Psychiatric illness and/or social situations that would limit compliance with study requirements
* HIV infection allowed provided patient meets the following criteria:

  * No evidence of co-infection with hepatitis B or C
  * CD4 cell count ≥ 400/mm³
  * No evidence of resistant strains of HIV
  * HIV viral load ≤ 10,000 copies HIV RNA/mL for patients not on anti-HIV combination antiretroviral therapy OR HIV viral load ≤ 50,000 copies HIV RNA/mL for patients on anti-HIV therapy
  * No history of AIDS-defining conditions
* No active secondary malignancy except for non-melanomatous skin cancer
* No other concurrent investigational agents
* Prior bendamustine hydrochloride allowed provided patient has completed a bendamustine-containing regimen within the past 6 months and achieved a partial response or better
* More than 4 weeks since prior chemotherapy or radiotherapy (6 weeks for nitrosoureas or mitomycin C) and recovered