P-186: Toxicity and survival outcomes of autologous stem cell transplant in Multiple Myeloma patients with renal impairment

Abstract

<h3>Background</h3> High dose therapy followed by autologous stem cell transplant (ASCT) remains a standard of care for eligible patients with multiple myeloma(MM) as it has been shown to deepen responses and prolong progression-free survival (PFS). There is some evidence to support the use of ASCT in patients with renal impairment and is recommended by IMWG for the management of MM in renally impaired patients. Some of the studies however, have shown increased risks associated with ASCT, coupled with somewhat poorer outcomes in this group of patients. Through this multicentre retrospective study, we demonstrate the feasibility of ASCT in patients with renal impairment (creatinine clearance <60ml/min) and document the safety, PFS and overall survival (OS) of this cohort, in comparison to patients who did not have renal impairment immediately prior to ASCT (CrCl≥60ml/min). <h3>Methods</h3> Patients with MM who had renal impairment at diagnosis who underwent ASCT between 2010-2018 were identified from the institutional disease registries. They were then stratified into 2 groups – the first cohort had renal impairment at diagnosis and at ASCT while the second cohort had renal impairment at diagnosis but with normal renal function prior to ASCT. The patient characteristics, safety and survival outcomes were collected and the data was analysed using STATA. A total of 50 patients were identified, 38 patients had renal impairment and 12 patients had normal renal function prior to ASCT. There was no difference in the baseline characteristics between both groups, including age, sex, prognostic scores (ISS, R-ISS), first line induction therapy, best response to first line therapy and mean peripheral blood stem cells collected. <h3>Results</h3> There was increased incidence of grade 3 or 4 neutropenia during ASCT (100% vs 83.3%, p=0.00) in the cohort of patients with renal impairment. However, this did not translate to increased febrile neutropenia episodes (73.7% vs 91.7%, p=0.19), or prolonged admission (20.7 vs 22.7 days, p=0.97). The incidences of serious grade 3 or 4 adverse events such as anaemia, thrombocytopenia, diarrhoea and vomiting were not different between both cohorts. The dose of melphalan used for ASCT was attenuated in patients with renal impairment (133mg VS 197mg, p=0.02). Despite this difference, the mean number of days taken for neutrophil and platelet engraftment were similar (11.0 vs 12.1 days p=0.02 and 14.1 vs 13.1days, p=0.97 respectively). Overall outcomes also did not differ between patients with renal impairment vs normal renal function, with comparable 3-year PFS (60.5% VS 58.3%, p=0.849) and 3- year OS (78.9% VS 83.3%, p=0.86). <h3>Conclusion</h3> Taken together, our cohort of patients with renal impairment had comparable toxicity profiles and overall outcomes as compared to patients with normal renal function. As such, ASCT should be considered in patients who present with renal impairment in line with the international recommendations so as to optimise their long-term outcomes.