Veliparib, Bendamustine Hydrochloride, and Rituximab in Treating Patients With Relapsed or Refractory Lymphoma, Multiple Myeloma, or Solid Tumors

Inclusion Criteria: * Phase 1b: Patients must have a histologically confirmed solid malignancy, lymphoma or multiple myeloma for which standard curative or palliative measures do not exist, are no longer effective, or for which the patient is not eligible or refuses; phase 1b cohort expansion: patients must have a histologically confirmed cluster of differentiation (CD)-20 positive B-cell non-Hodgkin lymphoma for which standard curative or palliative measures do not exist, are no longer effective, or for which the patient is not eligible or refuses; phase 2a: patients must have histologically or cytologically confirmed marginal zone B-cell lymphoma, small lymphocytic lymphoma, lymphoplasmacytic lymphoma or mantle cell lymphoma, and must have at least one measureable site of disease * For lymphoma and multiple myeloma patients: patients who have relapsed or are refractory to at least one prior chemotherapeutic regimen or biologic agent; patients must either be ineligible for or have refused curative options for treatment, including stem cell transplant, if applicable * For solid tumor patients: relapsed or refractory to at least one prior chemotherapeutic regimen or biologic agent; patients must either be ineligible for or have refused curative options for treatment * Patients must have had a rest period of at least 3 weeks since prior chemotherapy or radiation therapy, 6 weeks if the last regimen included carmustine (BCNU) or mitomycin C; there must be a rest period of at le…