Patterns of Renal Recovery and Toxicity with Novel Agent-Based Induction Triplets in Newly Diagnosed Multiple Myeloma - an Analysis of Two Prospective Studies By the German DSMM Myeloma Study Group

Introduction The kidney is an important target organ in plasma cell dyscrasias, subjected to various mechanisms of injury such as tubular obstruction, hypercalcemia, and pre-existing disease. Preservation of kidney function in newly diagnosed (ND) multiple myeloma (MM) is of concern as treatment-related toxicity (for instance infections and mucositis) is known to increase with renal impairment (RI). However, even severe MM-induced RI may recover with anti-myeloma treatment. We set out to compare three induction regimens in patients (pts) with transplant-eligible NDMM in terms of renal recovery and toxicity, MM response and associated adverse events (AEs). Pts from two prospective trials (NCT00833560, NCT01685814) were analyzed, provided post-induction (PInd) restaging data was available. They received three 3-week induction cycles with bortezomib (btz), cyclophosphamide, and dexamethasone (dex; VCD); btz, lenalidomide (len), and dex (VRD); or three 4-week cycles with len, adriamycin, and dex (RAD). All pts had to have measurable disease, an estimated glomerular filtration rate (eGFR) of >30 ml/min and to be up to 60 (VCD) and 65 years (yrs) of age, respectively. VCD consisted of intravenous (IV) btz 1.3 mg/m² on day (D) 1, 4, 8, 11; IV cyclophosphamide 900 mg/m2D1; dex 20 mg D 1+2, 4+5, 8+9, 11+12. VRD of subcutaneous (SQ) btz 1.3 mg/m² D 1, 4, 8, 11; len 25 mg, D1-14; dex 20 mg D 1+2, 4+5, 8+9, 11+12; and RAD of len 25 mg D1-21; IV adriamycin 9 mg/m² D1-4; dex 40 mg D 1-4 + 17-20. Methods This is a secondary analysis of a phase 2 and a phase 3 study. We hypothesized MM disease response (and in turn, renal recovery) would be best with VRD. GFR was estimated by the MDRD IV or CKD-Epi formulas. The increase (and decrease, respectively) of renal function expressed by “GFRpost induction- GFRscreening” was tested for significance (p