Lenalidomide Maintenance and Measurable Residual Disease in a Real-World Multiple Myeloma Transplanted Population Receiving Different Treatment Strategies Guided by Access to Novel Drugs in Brazil.

Despite recent advances in multiple myeloma (MM), the incorporation of novel agents and measurable residual disease (MRD) monitoring in low-income countries remains a challenge. Although lenalidomide maintenance (M-Len) after autologous stem cell transplantation (ASCT) has been associated with improved outcomes and MRD has refined the prognosis of complete response (CR) cases, until now, there have been no data on the benefits of these approaches in Latin America. Here, we evaluate the benefits of M-Len and MRD using next-generation flow cytometry (NGF-MRD) at Day + 100 post-ASCT (n = 53). After ASCT, responses were evaluated based on the International Myeloma Working Group criteria and NGF-MRD. MRD was positive in 60% of patients with a median progression-free survival (PFS) of 31 months vs. not reached (NR) for MRD-negative cases (p = 0.05). The patients who received M-Len continuously had a significantly better PFS and overall survival (OS) than those without M-Len (median PFS: NR vs. 29 months, p = 0.007), with progression in 11% vs. 54% of cases after a median follow-up of 34 months, respectively. In a multivariate analysis, MRD status and M-Len therapy emerged as independent predictors of PFS (median PFS of M-Len/MRD- vs. no M-Len/MRD+ of NR vs. 35 months, respectively; p = 0.01). In summary, M-Len was associated with improved survival outcomes in our real-world MM cohort in Brazil, with MRD emerging as a useful reproducible tool to identify patients at an earlier risk of relapse. The inequity in drug access remains a hurdle in countries with financial constraints, with a negative impact on MM survival.

Risk factors for unsuccessful peripheral blood stem cell harvesting using granulocyte-colony stimulating factor mobilization in patients with multiple myeloma.

The aim of this study was to determine factors that influence unsuccessful peripheral blood stem cell (PBSC) harvesting in patients with multiple myeloma (MM). Retrospective data of 186 MM patients who received G-CSF as mobilization were analyzed. Patients with successful harvest were compared with those who failed (using 2 definitions of failure <2 and <4 CD34 cells×10(6)/mm(3)). The groups were compared regarding age, gender, body weight, baseline platelet count, receipt of radiotherapy, number of prior chemotherapy regimens, PBSC count before collection, processed and collected volume, collect replace, number of sessions and final number of PBSC collected. By multivariate analysis, a baseline platelet count <161,000 cells/mm(3) was associated with PBSC harvest lower than 2×10(6)/kg, and age >58 years was related to PBSC harvest lower than 4×10(6)/kg CD34 cells/kg. Patients with these parameters should not receive mobilization protocols with G-CSF alone. Alternative protocols should be tested in this high risk harvest failure population.