Autologous stem cell transplant for multiple myeloma patients 70 years or older.

Autologous stem cell transplant (Auto-SCT) is increasingly used in older patients with multiple myeloma (MM), despite lack of phase 3 trials in this age-defined population. For 207 consecutive MM patients who underwent Auto-SCT and were 70 years or older at transplant (study cohort), data were analyzed and compared with a younger cohort (1764 Auto-SCT patients <70 years old). The proportion of Auto-SCT in the older patients increased from 7.8% of all transplants in 1998-2006 to 12.9% in 2007-2015. Sixty percent of patients required stem cell mobilization with chemotherapy or plerixafor. Full-dose melphalan conditioning was given to 55% of the older patients compared with 93% of the younger patients (P<0.001). Older patients were more likely to be hospitalized (64% vs 55%; P=0.01), but hospitalization duration was comparable. For newly diagnosed patients, median PFS was 33.5 months for the older cohort and 33.8 months for the younger cohort (P=0.91), and median overall survival was 6.1 and 7.8 years, respectively (P=0.11). Presumably, a smaller fraction of patients, age 70-76, is selected for Auto-SCT, but the benefits are comparable to those seen for younger patients. Reduced-dose melphalan was given to approximately half the patients to avoid excessive toxicity.