Risk Factors for Graft Failure in Children Undergoing Hematopoietic Cell Transplant (HCT) for Hemoglobinopathies, Bone Marrow Failure Syndromes, Severe Aplastic Anemia, Inborn Errors of Metabolism and Primary Immune Deficiencies

Introduction: Autologous stem cell transplantation (ASCT) with high-dose melphalan (HDM) is the standard consolidation treatment for transplant-eligible multiple myeloma (MM) patients. Many countries use generic melphalan (MEL) due to its low cost and easy availability. We previously reported the comparable pharmacokinetics and efficacy of generic and innovator MEL in a cohort of 65 patients from our center. Here, we present the updated data and long-term follow-up in an extended cohort of 120 patients. Methodology: Consecutive patients with MM receiving HDM were included in the analysis. Choice of MEL was based on patients' preferences and finances. Patient demographics, peri-transplant data, and short- and long-term outcomes data were captured from electronic medical records. MEL dosing was based on renal function as per standard guidelines. Results: This analysis included 120 patients (79 men and 41 women). The majority of the patients (n=96, 80%) had only one prior line of treatment before ASCT, and 93 patients (77.5%) achieved at least a very good partial response. Sixty-eight patients (56.7%) received generic MEL for conditioning. Neutrophil engraftment occurred earlier in the generic MEL group (11.40 days vs. 12.13 days, P=0.01). There were no differences in the incidence or severity of mucositis, platelet engraftment, or duration of hospitalization between the two groups. There were 3 deaths (2 in the generic group and 1 in the innovator group), all due to multidrug-resistant gram-negative infections. There were no differences in the response achieved on day 100. Progression-free and overall survival were similar between the two groups. Conclusions: Generic MEL is comparable to innovator MEL with respect to toxicity and long-term outcomes. It is an excellent alternative for the innovator to cut the cost of transplantation in developing countries.