2.Valme Hospital (Sevilla).
3.Reina Sofía Hospital (Córdoba).
4.Antequera Hospital (Málaga).
5.Jaén Complejo Hospitalario (Jaén).
6.Carlos Haya Hospital (Málaga).
7.Jerez Hospital (Jerez de la Frontera, Cádiz).
8.Virgen de la Victoria Hospital (Málaga).
9.Juan Ramón Jiménez Hospital (Huelva).
Background: The most common therapy in young multiple myeloma patients include induction, mobilization, collection and graft of peripheral blood stem cells. The present phase 2, multi-center, randomized study was designed to compare the results after four (arm A) and two (arm B) cycles of induction with lenalidomide plus dexamethasone as first line of treatment. The main aim of the study was to compare the number of collected stem cells for transplant between both arms.
Findings: Of the 31 initially included patients, 23 patients were evaluable, 11 and 12 patients in arm A and B, respectively. After induction and mobilization a non-significantly different mean of 4.30 x106 CD34+ cells/kg in arm A and 4.79 x106 CD34+ cells/kg in arm B were obtained (p=0.460), respectively. Although a lower number of CD34+ cells were obtained compared with previous studies, it was a sufficient yield for transplantation. The overall response rate was 94.8% and 93.9% at induction and at autologous stem cell transplantation (ASCT), respectively. No differences were observed between arms in the response rate, which was similar to that reported in previous studies. On the other hand, to sufficiently contrast differences in the overall survival and the progression-free survival endpoints, this study suffered from the limitation of the low number of patients followed.
Conclusion: Our study confirmed the existing results about grafts quality obtained with lenalidomide and the effectiveness of mobilization with cyclophosphamide and granulocyte colony stimulating factor (G-CSF), although wider randomized studies should confirm the extension and implication of the observations related to response rate, overall survival and progression-free survival.
Keywords: Multiple myeloma, lenalidomide, dexamethasone, peripheral blood stem cells, autologous transplantation, stem cell mobilization