9227 POSTER Simulation of Clinical Endpoints (Survival, PFS) in Patients With Refractory Multiple Myeloma Treated With Pomalidomide Based on Interim Week 8 M-protein Response

Abstract

relapse rate. We aimed to characterize alemtuzumab-based conditioning alloSCT patients in the Instituto Portugues de Oncologia do Porto (IPOP) and analyze the relation between MDC and alloSCT outcomes. Material and Methods: Retrospective analysis of consecutive patients admitted in the IPOP for alemtuzumab-based conditioning alloSCT between 1999 and February 2011. Data on donor chimerism were obtained on months 1, 3, 9 and 12. SPSS18 was used for statistics. Time to event data were analyzed by Kaplan-Meyer method and compared with log-rank test. Results: We performed 40 transplants in 38 patients (45% male). Median age was 27 years. Diagnoses were acute myeloid leukemia/myelodisplastic syndrome in 47%, lymphoma in 16% and non-malignant diseases in 28%. Status pre-alloSCT was complete remission in 35%, relapse in 13%, untreated in 35% and graft failure of a previous transplant in 15%; 22% had previous alloSTC. The commonest conditioning regimens were fludarabine-based (76%%). Donor was related sibling in 14. HLA was identical in 16. Stem cell source was peripheral blood in 30 and bone marrow in 8. Immunosuppression was based in a calmoudolin inhibitor in 29. Cytomegalovirus reactivation occurred in 50%. Six patients received donor lymphocyte infusion. Median duration of follow-up was 47 months. Median time to neutrophil and platelet engraftment was 14 and 11 days. Almost 50% had MDC at all-time points; 33% and 20% had acute and chronic GvHD. Median overall survival (OS) was 3.7 years. Estimated OS at 1 and 3 years was 58% and 46%. At the last contact, 10 of the 20 alive patients were in complete remission and 16 had died of transplantrelated causes, with 100 days and 1 year transplant-related mortality (TRM) of 19% and 41%. Relapse risk in malignant disorders was at 1 and 5 years 26% and 40%. Presence of MDC was associated with lower acute GvHD risk (p = 0.47) but found to be not related to risk of relapse, OS and TRM. Conclusions: Alemtuzumab-based conditioning regimen wasn’t related to relapse risk or OS, so it can be used in selected high risk patients. Our series differs from others in the greater diversity of diseases and conditioning regimens and higher percentage of unrelated donor transplant, non-identical HLA match and previous alloSTC. These characteristics, in association with our limited sample size, can justify the differences in results, particularly the higher TRM.