Efficacy and safety of autologous hematopoietic cell transplantation in elderly patients with multiple myeloma: a retrospective national multi-site cohort study

We aimed to test the efficacy and toxicity of autologous hematopoietic cell transplant (HCT) in Multiple Myeloma (MM) patients aged ≥65 years compared to patients aged 60–64. Two hundred twenty consecutive patients (age ≥65, n = 87) with MM aged 60 and above, who underwent HCT as part of an upfront MM treatment, at four Israeli centers between 2000 and 2014 were included. A melphalan dose of 200 mg/m² was more frequent in the 60–64 age group vs. the ≥65 age group (77 vs. 57%, p = 0.002). There were no differences between groups in median day of neutrophil engraftment, incidence of infections, grades 3–4 mucositis, cardiovascular events, or non-relapse mortality at 100 days post HCT (4.7, vs. 5%, p = 0.9). A similar rate of improvement in response level was observed (36, vs. 35%, p = 0.87). At 3 years post HCT progression-free survival (PFS) was higher in the 60–64 age group (42 vs. 29%, p = 0.04); however, it was no longer so after adjustment for disease status prior to HCT (p = 0.49). In a Multivariate analysis, melphalan doses and age did not predict PFS. There was no difference in overall survival (OS) between age groups (p = 0.2). We conclude that toxicity profile, response, PFS, and OS of HCT in aged ≥65 patients with myeloma is similar to patients aged 60–64.