BackgroundMelphalan formulated with modified cyclodextrin (β-cyclodextrin sulfobutyl ether sodium [BSES]) is widely used before autologous stem cell transplantation (ASCT) in patients with multiple myeloma (MM) because of its favorable solubility and stability versus conventional melphalan, but the efficacy and safety data on Chinese patients with MM who subsequently underwent ASCT are still limited.MethodsIn this prospective, open-label, non-randomized, interventional study, a total of 67 MM patients who were eligible for ASCT were enrolled and assigned to receive 200 mg/m2 of Melphalan in two divided doses of 100 mg/m2 on Days -3 and -2 before ASCT on Day 0. We evaluated the efficacy, safety and pharmacokinetics (PK) of a prolonged infusion of high-dose BSES-melphalan as the conditioning treatment in the patients.ResultsOverall, 67 patients received melphalan with the median infusion time of 136 min. All patients achieved myeloablation with a median time of 5 days. Median time to neutrophil and platelet engraftments was 11 and 12 days after ASCT, respectively. Within the 65 evaluable patients, 18 patients (27.7%) achieved stringent complete response, 21 (32.3%) achieved complete response, 18 (27.7%) achieved very good partial response, and 3 (4.6%) achieved partial response. No treatment-related mortality (TRM) or adverse events leading to study withdrawal were identified. Prolonged infusion resulted in a lower Cmax but comparable AUCs.ConclusionsHigh-dose BSES-melphalan as a conditioning medicine is effective and safe in Chinese patients with MM before ASCT. Prolonging infusion duration may improve the safety without compromising efficacy.