Obinutuzumab With or Without Umbralisib, Lenalidomide, or Combination Chemotherapy in Treating Patients With Relapsed or Refractory Grade I-IIIa Follicular Lymphoma

Inclusion Criteria: * Patients must have follicular lymphoma (grade I, II or IIIa) confirmed at initial diagnosis and at relapse with identifiable fludeoxyglucose F-18 (FDG) avid disease on PET/CT; patients that have involvement with large cell lymphoma are not eligible * Patients must have a whole body or limited whole body PET/CT scan performed within 42 days prior to registration * Patients must have bone marrow biopsy performed within 42 days prior to registration * Patients must have an indication for therapy as determined by the treating investigator * All disease must be assessed and documented on the S1608 FDG-PET/CT assessment form * The intent is to enroll patients with follicular lymphoma (FL) relapsed within 2 years of completing their first course of chemotherapy (CHOP or bendamustine based therapy) + anti-CD20 therapy. Patient is still eligible if he/she received radiation therapy or anti-CD20 therapy prior to chemoimmunotherapy or if maintenance anti-CD20 therapy was administered after chemoimmunotherapy * Patients must have either failed to achieve a complete remission, or must have relapsed within 2 years after completing CHOP or bendamustine-containing chemoimmunotherapy (including an anti-CD20 monoclonal antibody), as measured from the last dose of CHOP or bendamustine; relapsed patients must not have received any intervening chemotherapy * Patients must have received only 1 course of chemotherapy, containing at least 3 cycles of CHOP or bendamustine;…