Suggested algorithm for the treatment of multiple myeloma at first relapse. Bort, bortezomib; DRD, daratumumab- lenalidomide-dexamethasone; KCd, carfilzomib-cyclophosphamide-dexamethasone; Len, lenalidomide; VD-PACE, bortezomib- dexamethasone-cisplatin-doxorubicin-cyclophosphamide-etoposide.