Outcome of IgD Myeloma After Autologous Hematopoietic Stem Cell Transplantation.

Abstract 4354 BACKGROUND Multiple Myeloma (MM) is a clonal disorder of plasma cells characterized by monoclonal immunoglobulin (Ig) secretion. Immunoglobulin D (IgD) MM constitutes <2% of all myeloma cases and is characterized by a younger age, male predominance, frequent extra osseous disease, amyloidosis, renal insufficiency and a poor prognosis. We retrospectively analyzed the outcome of patients with IgD myeloma transplanted at our institution. METHODS Between August 1988 and June 2008, 15 patients with IgD MM (13 males, 2 females) received autologous hematopoietic stem cell transplantation (auto HCT) at MD Anderson Cancer Center. Twelve patients received high-dose melphalan (200 mg/m2) as preparative regimen; 3 patients received high-dose melphalan in combination with other agents. RESULTS At diagnosis 7/15 (47%) patients had Durie-Salmon stage III disease, 6/15 (40%) had serum creatinine ≥2 mg/dl and 6/15 (40%) had hypercalcemia. Median age at the time of auto HCT was 53 yrs (range 38–64 yrs) and median interval between diagnosis and auto HCT was 12.6 months (range 3-75 months). Prior to auto HCT 11 patients achieved a partial remission (PR), one had a very good partial remission (VGPR), 2 had minimal response (MR) and one patient had no response to induction. Median follow-up in surviving patients was 25 months. Median time to neutrophil engraftment (ANC > 500/dl) was 10 days (range 9–15 days) and for platelet engraftment (>20,000/dl) was 11 days (range 8–16 days). Non-relapse mortality at 100 days was 0%. Complete responses were seen in 6/15 (40%) patients; 3 converted from PR to CR, 2 from MR to CR and one from VGPR to CR. Only one patient progressed within 3 months of auto HCT. Kaplan-Meiers estimates of 3-year progression-free survival (PFS) and overall survival (OS) were 38% and 64%, respectively. Median time to progression was 18 months. One patient with complex cytogenetics including deletion 13q had disease progression 7 months following an auto HCT. He subsequently received an allogeneic transplant, achieved stable disease status and died 11 months later due to progressive disease. Another patient received a second auto HCT for relapse, but died 3 months later due to progressive disease. CONCLUSIONS Patients with IgD MM, despite a higher incidence of renal insufficiency and hypercalcemia at diagnosis, can safely receive auto HCT, with overall response rates, PFS and OS comparable to other MM subtypes. Disclosures: Shah: Celgene, Amgen, Novartis, Elan: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding.