Lenalidomide, Dexamethasone and MEDI-551 in Untreated Multiple Myeloma

Inclusion Criteria:

* Age 18 to 100 years at the time screening
* Symptomatic, previously untreated (with exception of corticosteroids) secretory myeloma
* Written informed consent obtained from the patient/legal representative prior to performing any protocol-related procedures, including screening evaluations
* Patient must agree to take Lenalidomide with low dose dexamethasone as their initial therapy.
* Eastern Cooperative Oncology Group (ECOG) performance status of 0, 1, or 2.
* Life expectancy of \>6 months
* Serum creatinine ≤ 2
* ANC≥1000
* Platelets ≥ 50,000
* Total bilirubin ≤ 2 x upper limit of normal (ULN)
* Aspartate aminotransferase (AST) and Alanine aminotransferase (ALT) ≤ 3 x ULN
* Able to take aspirin (81 or 325 mg) daily as prophylactic anticoagulation (patients intolerant to aspirin may use warfarin or low molecular weight heparin)

Exclusion Criteria:

* Any condition that, in the opinion of the investigator, would interfere with evaluation of the investigational product or interpretation of patient safety or study results.
* Concurrent enrollment in another clinical study, except for non-interventional, observational studies.
* Any chemotherapy, immunotherapy, biologic, investigational, for treatment of multiple myeloma other than Lenalidomide and dexamethasone.
* Previous monoclonal antibody (mAb) or other treatment specifically directed against cluster of differentiation antigen 19 (CD19).
* History of serious allergy or reaction to any component of the MEDI-551 formulation that would prevent administration.
* Previous systemic cancer therapy for myeloma.
* Any active secondary malignancy.
* Human immunodeficiency virus (HIV) positive serology or acquired immune deficiency syndrome.
* Active hepatitis B as defined by seropositivity for hepatitis B surface antigen. Or patients with positive hepatitis B core antibody titers.
* Patients with hepatitis C antibody will be eligible provided that they do not have elevated liver transaminases or other evidence of active hepatitis.
* Documented current central nervous system involvement by multiple myeloma.
* Previous medical history or evidence of an intercurrent illness that may, in the opinion of the investigator, compromise the safety of the patient in the study.
* Diagnosis of plasma cell leukemia
* Diagnosis of POEMS syndrome
* Diagnosis of Amyloidosis
* Diagnosis of non-secretory myeloma