NON-Cryopreserved Hematopoietic STEM CELL Transplantation in Multiple Myeloma. a Single Center Experience in Oran (ALGERIA)

Introduction:

For younger patients under 65 years of age, induction followed by high-dose chemotherapy with autologous stem cell transplantation (ASCT) is the standard treatment in multiple myeloma (MM). There is limited experience with non-cryopreserved autologous hematopoietic stem cell transplantation. We evaluated the efficacy and safety of non-cryopreserved storage of ASCT in patients undergoing ASCT for MM.

Patients and methods:

Autologous stem cell was mobilized using G-CSF alone (10 µg/kg/day for 5 days). Leukapheresis to harvest stem cells were performed on day -2 and -1. The grafts were kept in a conventional blood bank refrigerator at +4°C until reinfusion on day 0. The conditioning regimen consisted of melphalan 200 mg/m² in all patients.

Results:

From May 2009 to December 2013, 134 patients with MM were treated in our center in Oran. The median age at ASCT was 55 years (range; 27-67). There were 80 males and 54 females. The median harvested CD34⁺ cell count was 3,5x10⁶/kg (range; 1, 22 to 13, 24). All patients had engraftment on the median of day 10 (range; 7 to 17) and platelet transfusion independence on the median of day 13 (range; 9 to 24). There was no graft failure. Mucositis grade 3/4 was seen in 68% patients. Transplant related mortality at 100 days was 2.9%. The overall response to transplant was 92%.

In the 130 evaluable patients, the median post-transplant overall survival had not been reached. The estimated overall survival at 75 months was 63% with 95% confidence interval and the median post-transplant disease free Survival was 35 months (0.05%). 93 (72%) patients are alive and 75 (81%) without disease activity after a median follow-up of 35 months (range; 3 to 75).

Discussion:

We conclude that high dose chemotherapy and autologous transplant with non cryopreserved ASCT is a simple, effective and safe method for MM with equivalent results, and that cryopreservation is not necessary in the treatment of MM under our work conditions in developing countries