- Abstract We compared the tolerability and anti-myeloma effect of 2 conditioning regimens for auto-SCT in consecutive groups of patients. Protocol 1 was the earlier and consisted of the combination of 3 agents in a sequential manner including etoposide, thiotepa and melphalan (n=29), while protocol 2 employed melphalan alone (n=34). The 2 groups were comparable (other than younger age in protocol 1). Conditioning with protocol 1 seemed more toxic as expressed by the higher number of febrile days and higher demand for parenteral nutrition. This was not expressed in higher number of admission. With a 108 and 60 months median follow-up respectively, the median survival in patients treated by protocol 2 (melphalan 200mg/m2) was reached at 59 months, while the median survival was not yet reached in patients treated with protocol 1 (p=0.039). The time to progression was significantly longer with protocol 1 (median 44 months vs. 17 months with protocol 2, p=0.033). Confounded by the small number of patients, conditioning with melphalan augmented by etoposide and thiotepa in a sequential manner is slightly more toxic than melphalan alone and may benefit myeloma patients undergoing auto-SCT.