Optimizing Autologous Hematopoietic Stem Cell Transplantation for Multiple Myeloma: Early Step-Down Ward Versus HEPA-Filtered Rooms: A Practical Approach for Resource-Limited Settings

Abstract

Autologous stem cell transplantation (ASCT) is a cornerstone treatment for multiple myeloma (MM). Implementing outpatient ASCT in lower- and middle-income countries (LMICs) remains challenging due to elevated infection risks, socioeconomic limitations, and logistical hurdles. Due to the limited number of high-efficiency particulate air (HEPA)-filtered rooms for ASCT in Thailand, an early step-down ward model could be an important innovation to increase the number of patients receiving timely ASCT. We performed an observational cohort study of all MM patients undergoing ASCT between January 2017 and October 2023. We compared the rates of infectious complications, engraftment outcomes, and treatment-related mortality (TRM) among patients after implementing the early step-down ward model, the step-down group, to those before its implementation, the pre-step-down group. Two hundred- and fifty-two-MM patients were analyzed, including 114 pre-stepdown group and 138 step-down group patients. The rate of ASCTs comparing the pre-step-down and step-down groups was 30-40/year and 85-100/year, respectively. The univariable cumulative mean infection rates were similar between the pre-step-down and step-down groups (1.27 per patient; 95% CI 1.02, 1.52 versus 1.18 per patient; 95% CI 1.07, 1.28, respectively). The adjusted relative density of infections comparing the groups was not different at 1.02 (95% CI 0.89, 1.17; P = .75). The 30- and 100-day TRM rates were 0% in both groups. Engraftment outcomes were similar in both groups. Rates of mold infections, severe infections, and intensive care unit admissions during admission for ASCT and 14-day re-admissions for infectious complications in the early step-down ward model patients were low and were comparable to or lower than the pre-stepdown group. Infectious complication rates and TRM rates were similar between patients exclusively staying in HEPA-filtered rooms post-ASCT and those under the early step-down-ward model. The model is feasible and safe for implementation in resource-limited LMICs. Keeping multiple myeloma patients in high-efficiency particulate air-filtered rooms after autologous stem cell transplant limits the number of patients undergoing transplantation in resource-limited settings, and may not be necessary for good infection control. We implemented an early step-down ward model, moving patients early from high-efficiency particulate air-filtered rooms to a step-down ward a few days after transplantation. Our model had similar rates of infectious complications, engraftment outcomes and treatment-related mortality comparing patients staying only in high-efficiency particulate air-filtered rooms. The early stepdown-ward model demonstrates safety and efficacy in reducing length of stay in transplantation units while increasing access to autologous stem cell transplantation for multiple myeloma patients in resource-limited settings. Furthermore, this approach can be implemented for autologous stem cell transplantation in non-HEPA-filtered rooms, offering a viable solution for lower- and middle-income countries where HEPA-filtered facilities are unavailable.