Kumar, Santosh

e19513 Background: The outcome of patients with MM relapsing after ASCT used early in the disease course or after failure of initial therapy, is not well defined. We undertook this study to understand treatment approaches for patients relapsing after single ASCT. Methods: Patients relapsing after single ASCT were identified from a prospectively maintained database and relevant clinical data were extracted from medical records. Relapse and treatment responses were according to IMWG Uniform Response Criteria. Patients relapsing between Jan 2000 and 2008 were included in order to capture a recent cohort contemporaneous to availability of novel drugs. Results: We studied 487 patients who had relapsed following a single ASCT, of whom 351 (72%) had an early SCT (≤ 12 mos from diagnosis). The median estimated follow up for all patients was 27 mos, 50 mos and 69 mos from relapse, SCT and diagnosis respectively. The median overall survival (OS) from the time of relapse was 30 mos for the early SCT group and 21 months for the late SCT group. The median time to relapse following transplant was 15 mos (3–119) among early SCT group and 12 mos (3–76) among the late SCT group. Longer time to relapse as well as longer time from relapse to initiation of therapy were independent predictors of better outcome. Among the early group, nearly a third of the patients achieved a PR or better to first salvage therapy (Table), with another third achieving stable disease and 25% of patients did not have response data. The median progression free survival for the first salvage regimen was 8 mos; 18 mos for those with PR or better and 5 mos for those with SD as the best response. Data on the regimen 2, 3, 4, 5, and 6 were available for 211, 133, 84, 53 and 28 patients respectively. As expected, the response rates and the response duration decreased with increasing number of relapses. Conclusions: Patients relapsing after ASCT can obtain prolonged response duration with the currently available treatments. Those with a durable response to transplant and those not requiring initiation of therapy for long periods after disease relapse have favorable disease biology and have prolonged survival after relapse. The natural history of the disease provides a valuable benchmark for evaluation of newer treatment approaches. No significant financial relationships to disclose.

8022 Background: Autologous stem cell transplant (ASCT) is the standard approach for eligible patients (pts) with multiple myeloma (MM). The median time to relapse after early ASCT is 2–3 yrs and overall survival (OS) is 4–5 yrs. Though various risk factors have been identified for early relapse, the outcome of this group of pts is not clearly described. With the advent of newer therapies, it is important to understand the natural history of MM in these pts to design treatment strategies. Methods: A total of 432 pts with MM, undergoing ASCT within 12 months (mos) of diagnosis, with a minimum follow up of 12 mos were studied. Clinical and laboratory data were obtained from a prospectively maintained database and clinical records. Pts were divided into 2 groups: early relapse (relapse <12 mos from ASCT) and late relapse (either relapsed >12 mos after ASCT or disease free at last follow up). Results: There were 94 pts (22%) in the early relapse group and among the late relapse group (N=338), 171 had relapsed beyond 12 mos and 167 were disease free at last follow up. The median time to ASCT was similar in all groups. The early relapse group had a significantly shorter median OS from diagnosis (23.9 vs. 82.2 months; P < 0.001) and from transplant (17.6 mos vs. not reached; P < 0.001). The median OS from relapse was 7.9 mos in this group compared to 39.6 months for the rest. In univariate analysis, elevated CRP, high BM plasma cell%, labeling index (PCLI) >1%, abnormal cytogenetics, presence of circulating PCs at harvest and lack of CR from ASCT predicted for early relapse. In multivariate analysis, an elevated PCLI (RR=2.9; P=0.002) and failure to achieve CR (RR 2.7; P=0.002) was associated with early relapse. Conclusions: Pts who relapse within 12 mos of an ASCT have a very short survival and should be offered trials evaluating novel therapies and combinations. Survival figures from this study represent the benchmark for the comparison of novel approaches in this population. Pts with poor prognostic factors have a short PFS after ASCT and should be considered for alternative approaches. Inability to achieve CR appears to predict shorter PFS and clinical trials evaluating maintenance therapy should be offered in these pts. No significant financial relationships to disclose.