Phase II Study of Daratumumab Based Response Adapted Therapy for Older Adults With Newly Diagnosed Multiple Myeloma

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.

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 will be given orally on days 1-21 of a 28 days cycle. The starting dose of lenalidomide will be based on the patient creatinine clearance per the package insert. 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, that study therapy is in the best interest of the patient and after discussion with the study principal investigator / sponsor.

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.