A Study of CyBorD (Cyclophosphamide, Bortezomib, Dexamethasone) Plus Daratumumab in People With Monoclonal Gammopathy of Renal Significance (MGRS)

This study tests a combination of four drugs — cyclophosphamide, bortezomib, dexamethasone, and daratumumab — in patients with a condition called monoclonal gammopathy of renal significance (MGRS), in which abnormal proteins produced by plasma cells cause kidney damage. This includes patients with kidney-damaging forms of multiple myeloma as well. **You may be eligible if...** - You are 18 or older - You have a kidney biopsy-confirmed diagnosis of MGRS-related kidney disease or myeloma-related kidney cast nephropathy - Your kidney function is significantly reduced (eGFR below 40) - Your blood counts, liver function, and other lab values meet required minimums - You are willing to use contraception as required **You may NOT be eligible if...** - You have MGRS linked to conditions other than plasma cell disease (e.g., leukemia or Waldenstrom's) - You have AL amyloidosis, plasma cell leukemia, or POEMS syndrome - You have previously received treatment targeting the plasma cell disorder - You have HIV, active hepatitis B or C, or cirrhosis - You have significant peripheral neuropathy (nerve damage) - You had major surgery or radiation in the past 2 weeks - You are pregnant or breastfeeding Talk to your doctor to see if this trial is right for you.