Evaluating the adverse effects of melphalan formulations

Area of Science:

• Hematology
• Oncology
• Pharmacology

Background:

• Autologous hematopoietic stem cell transplant (HSCT) is standard for multiple myeloma patients responding to primary therapy.
• High-dose melphalan conditioning is used in HSCT, with two formulations available: propylene glycol-containing (PG-MEL) and propylene glycol-free (PG-free MEL).
• Limited data exist on the comparative adverse events of these melphalan formulations in real-world settings.

Purpose of the Study:

• To assess and compare the tolerability and severity of side effects between PG-MEL and PG-free MEL in multiple myeloma patients undergoing HSCT.
• To evaluate potential differences in hematologic toxicity, gastrointestinal toxicity, renal toxicity, and mucositis grade.

Main Methods:

• Retrospective, descriptive analysis of 78 multiple myeloma patients undergoing HSCT.
• Patients received two doses of melphalan at 100 mg/m² per dose.
• Primary outcome: assessment of tolerability and side effect severity, categorized by hematologic, gastrointestinal, and renal toxicity, and mucositis grade.

Main Results:

• Median time to myeloablation was 5 days and neutrophil engraftment was 7 days post-HSCT across all patients.
• Patients receiving PG-free MEL showed a statistically significant lower incidence of mucositis (56% grade 0) compared to PG-MEL (33% grade 0), p=0.04.
• Overall, minimal differences in tolerability and side effects were observed between the two melphalan formulations.

Conclusions:

• PG-free MEL and PG-MEL demonstrated largely similar tolerability profiles and adverse event rates in this patient cohort.
• The findings suggest that both melphalan formulations are comparable in terms of safety for high-dose conditioning therapy in HSCT for multiple myeloma.
• These real-world data contribute to understanding the adverse effects associated with high-dose melphalan conditioning.