(PA-399) Survival Outcomes and Safety of High-dose Melphalan with Autologous Stem Cell Transplantation in Multiple Myeloma: A Retrospective Study

High-dose therapy (HDT) followed by autologous stem cell transplantation (ASCT) improves overall survival (OS) in multiple myeloma compared to standard-dose therapy (SDT), particularly before novel agents emerged. Benefits of HDT-ASCT are more pronounced in high-risk cytogenetics. ASCT is safe, with low treatment-related mortality (~1%).

Aims and

Objectives: This study aimed to retrospectively evaluate survival outcomes among multiple myeloma patients undergoing HDT-ASCT. Objectives included analysing clinical features and assessing PFS and OS.

Methods:   

A retrospective analysis was conducted on 186 multiple myeloma cases undergoing HDT-ASCT at  a  tertiary care centre ,Jaslok Hospital and Research Centre,Mumbai,India  between 2001 and March 2024. Clinical and laboratory data were analysed using SPSS v22.0 with appropriate statistical tests.

Results:   

The cohort included 186 patients, mostly male (70.97%) and predominantly under 60 years (87.09%). At transplantation, 74.19% achieved a very good partial response (VGPR) or better. IgG Kappa was the most common M-protein (36.56%). ISS stage III disease occurred in 25.80%, and high-risk cytogenetics in 31.72%. Newly diagnosed multiple myeloma accounted for 75.80% of cases. Melphalan doses administered were 200 mg/m² in 72.04% (n=134) and 140 mg/m² in 52 patients. Hospital stays were significantly longer with 200 mg/m² (22.82 days) versus 140 mg/m² (19.15 days; P< 0.05). Mean neutrophil engraftment times were comparable (12.54 days at 140 mg/m²; 12.90 days at 200 mg/m², P >0.05), as were platelet engraftment times (14.18 vs. 14.33 days; P >0.05). Grade 3 or higher mucositis rates were similar between doses (20.6% at 140 mg/m² and 21.7% at 200 mg/m², P=1.000). Treatment-related mortality was low (1.61%, n=3). Median overall survival was 60.1 months (95% CI: 44.8–71.8), and median progression-free survival was 51.2 months (95% CI: 42.1–61.9).

Conclusions:   

HDT-ASCT demonstrates substantial clinical benefit and safety, supporting its routine use in eligible NDMM and RRMM patients in India.