The impact of renal function on initial therapy in transplant-ineligible multiple myeloma patients

The prognosis for multiple myeloma (MM) patients has improved with the advent of new drugs, but the prognosis with renal impairment (RI) is poor. The choice of treatment in such cases is critical, but there are no set criteria. We examined the impact of RI on initial therapy in transplant-ineligible MM patients. We selected symptomatic MM patients who met the following criteria: age ≥ 65 years, fit, and ineligible for transplantation from the database. We analyzed the impact of age, treatment, International Staging System (ISS) stage, karyotype abnormalities, performance status, and estimated glomerular filtration rate (GFR < 50 or ≥ 50 ml/min/1.73m²) on overall survival (OS). We also analyzed the OS by eGFR for each treatment. We selected 349 symptomatic MM patients. The regimens used were lenalidomide, bortezomib and dexamethasone (RVd), daratumumab, bortezomib, melphalan, and prednisolone (D-VMP), daratumumab, lenalidomide and dexamethasone (D-Rd) and daratumumab, bortezomib, and dexamethasone (D-Vd) in 184, 41, 74 and 50 patients, respectively. The median age was 74 years old; ISS stage was I/II/III in 85/112/131 patients; and 161 patients showed eGFR < 50. The OS was shorter with ISS stage III (p = 0.029) and eGFR < 50 (p < 0.001) by multivariate analysis. The OS under the RVd/D-Rd regimens were significantly shorter for patients with eGFR < 50, but OS under the D-VMP/D-Vd regimens were not significantly different between patients with eGFR < 50 and eGFR ≥ 50. The OS of the transplant-ineligible MM patients with higher ISS stage and RI was poor. Initial treatment with a D-VMP/D-Vd regimen might be less affected by RI.