Evaluation of High-Dose Melphalan Toxicity by Age in Patients Undergoing Autologous Stem Cell Transplant for Multiple Myeloma

Abstract

Introduction Melphalan 200 mg/m2 on day -2 (Mel 200) is the standard conditioning regimen in autologous stem cell transplant (ASCT) for multiple myeloma (MM). This regimen is associated with significant gastrointestinal (GI) toxicity, including diarrhea, vomiting, and mucositis; therefore the dose may be reduced to 100-140 mg/m2 based on performance status or age. As the true difference in GI toxicity in older vs. younger patients is unknown, dose reductions may unnecessarily compromise efficacy outcomes. The objective of this study was to define the incidence of GI toxicity in patients age ≥ 60 vs. patients age Objectives Review dose adjustments for melphalan conditioning prior to ASCT in MM. Identify toxicities associated with melphalan conditioning for ASCT in MM. Compare melphalan toxicity between patients age ≥ 60 vs. patients age Methods A retrospective cohort study was conducted via medical record review of adult patients treated with Mel 200 followed by first ASCT for MM from September 2012 to September 2017. The primary endpoint was incidence of GI toxicity, defined by Common Terminology Criteria for Adverse Events (CTCAE) grade 2 or higher diarrhea or grade 3 or higher mucositis during transplant admission. Secondary endpoints included subdivided primary endpoints, complete response rates, and measurements of recovery. Subgroup analyses were performed for patients age ≥ 65, and patients with renal impairment. Results A total of 167 patients were included, with 116 patients in the age Conclusion This single-center, retrospective medical record review demonstrated that patients older than age 60, particularly those 60 to 65 years of age, may receive Mel 200 with no difference in the incidence of GI toxicity compared to younger patients. Further study in a larger population of patients age 65 or older is needed to establish conclusions in this patient population.