Adverse events

All participants will receive 1800 mg in 15 ml Daratumumab by subcutaneous injection weekly and be given 20 mg of Dexamethasone orally once a week for 2 months. Patients who receive a partial response or better will continue on this arm. Daratumumab Injection: Patient will receive daratumumab (1800 mg in 15 ml) administered by manual subcutaneous injections weekly for the first 8 weeks, every other week for the next 16 weeks and every 4 weeks after. Dexamethasone Oral: The dexamethasone starting dose will be 20 mg PO once a week. Commercial dexamethasone will be used. Dexamethasone is often supplied in 4 mg tablets. Accordingly, patients will take 5 (4 mg tablets) one day of the week prior to the administration of daratumumab if this corresponds to a daratumumab dosing days. In non daratumumab dosing days, dexamethasone will be taken by the patient at home, usually in the morning with breakfast.

Participants who have less than a partial response to Arm A may have Lenalidomide added to their treatment. Lenalidomide will be given orally on days 1-21 of each 28 day treatment cycle. Daratumumab Injection: Patient will receive daratumumab (1800 mg in 15 ml) administered by manual subcutaneous injections weekly for the first 8 weeks, every other week for the next 16 weeks and every 4 weeks after. Dexamethasone Oral: The dexamethasone starting dose will be 20 mg PO once a week. Commercial dexamethasone will be used. Dexamethasone is often supplied in 4 mg tablets. Accordingly, patients will take 5 (4 mg tablets) one day of the week prior to the administration of daratumumab if this corresponds to a daratumumab dosing days. In non daratumumab dosing days, dexamethasone will be taken by the patient at home, usually in the morning with breakfast. Lenalidomide Pill: Lenalidomide will be given orally on days 1-21 of a 28 days cycle. Specifically patients with a creatinine clearance ≥ 50 ml/min will receive 25 mg of lenalidomide PO Days 1-21. Patients with a creatinine clearance ≥ 30 but less than 50 ml/min will receive 10 mg of lenalidomide. Patients with a creatinine clearance \< 30 ml/min are not eligible but patients who experience a deterioration in the renal function during screening or treatment may continue on lenalidomide therapy as long as the risk / benefit profile is deemed acceptable.

Participants who have less than a partial response to Arm A may have Bortezomib added to their treatment. Bortezomib will be given weekly in subcutaneous injections at a starting dose of 1/3 mg/m\^2 Days 1,8 and 15 of each 28 day treatment cycle. Daratumumab Injection: Patient will receive daratumumab (1800 mg in 15 ml) administered by manual subcutaneous injections weekly for the first 8 weeks, every other week for the next 16 weeks and every 4 weeks after. Dexamethasone Oral: The dexamethasone starting dose will be 20 mg PO once a week. Commercial dexamethasone will be used. Dexamethasone is often supplied in 4 mg tablets. Accordingly, patients will take 5 (4 mg tablets) one day of the week prior to the administration of daratumumab if this corresponds to a daratumumab dosing days. In non daratumumab dosing days, dexamethasone will be taken by the patient at home, usually in the morning with breakfast. Bortezomib Injection: Bortezomib will be given weekly subcutaneously in an effort to decrease the toxicity of the therapy. Specifically patients will receive a starting dose of bortezomib of 1.3 mg/m\^2 Days 1,8,15 of a 28 day cycle. Bortezomib will be administered in the cancer center per standard of care procedures.