Myeloma (MM) after autologous transplant (AutoHCT): Biochemical versus clinical progression

e18575 Background: Maintenance therapy after AutoHCT improves progression free but not overall survival in MM. Close monitoring and preemptive treatment at biochemical progression may delay clinical relapse of MM while reducing overall drug exposure. However the interval from biochemical to clinical progression is not generally studied, and limits the feasibility of such a preemptive strategy. Methods: In order to analyze patterns of relapse after AutoHCT, we studied biochemical and clinical relapse in 97 AutoHCT recipients with MM. Patients (pts) were monitored with q 3mo serum free light chain, protein electrophoresis and annual bone studies interpreted by standard IMWG criteria. Results: Median age was 60 (47-77), 61% male and 20% with light chain myeloma. Characteristics of the upfront transplant cohort (69%) at diagnosis: International Staging System (ISS) Stage III in 41%, median values of beta2-microglobin (b2m) 3.26, albumin 3.8, high-risk cytogenetics in 35%. Recipients of salvage AutoHCT ( 31%) ...