Lab tests could pick the right drug for tough myeloma cases

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Diagnosis of multiple myeloma or plasma cell leukemia with documented relapsed or refractory disease according to International Myeloma Working Group (IMWG) criteria, in any one of the following categories: * 3 prior lines of therapy including an immunomodulatory drug (IMiD) and a proteasome inhibitor (PI) * Less than a very good partial response (VGPR) to initial therapy * Early relapse (\< 12 months) after autologous hematopoietic cell transplant (HCT) or after 1st line of therapy * Collection of a bone marrow, fluid or tissue sample that is expected to have enough cells to run the assay * Measurable disease defined by one of the following: * Serum monoclonal protein \>= 0.5 g/dL by serum protein electrophoresis (SPEP) * \>= 200 mg/monoclonal protein in urine on 24 hr urine protein electrophoresis (UPEP) * Involved serum free light chain (FLC) \>= 10 mg/dL and abnormal involved:uninvolved ratio * Plasma cytomas that are palpable per exam or measurable per standard radiologic review * Circulating plasma cells \>= 2,000 if diagnosis of plasma cell leukemia * Eastern Cooperative Oncology Group (ECOG) performance status (PS) 0-3 * Female patients of child bearing potential and non-vasectomized male patients agree to practice appropriate methods of birth control * Ability to understand purpose and risks of the study and provide signed and dated informed consent, and authorization to use protected health information * Expected survival is \> 100 days * Adequate organ function as determined by the investigator Exclusion Criteria: * Mucosal or internal bleeding, or platelet transfusion refractory * Any medical conditions that would impose excessive risk to the patient, or would adversely affect his/her participation in the study * Known active infection requiring antibiotics within 7 days of initiation of study treatment, unless considered controlled in the opinion of the investigator * Other malignancy with life expectancy \< 1 year due to the other malignancy * Pregnant or breast feeding women * Serious psychiatric illness, alcoholism, or drug addiction * Human immunodeficiency virus (HIV), or active hepatitis B or C infection * Previous treatments for multiple myeloma (MM) within 2 weeks of initiation of study treatment * Prior autologous or allogeneic stem cell transplantation (SCT) within 12 weeks of initiation of study treatment * Prior allogeneic hematopoietic cell transplantation (HCT) with active graft versus host disease (GVHD) on therapeutic dosing of immunosuppression or prednisone \> 20 mg daily equivalent * Prior major surgical procedure or radiation treatment within 2 weeks of initiation of study treatment (not including limited radiation used for palliation of bone pain)