Durable remission with salvage second autotransplants in patients with multiple myeloma

Background: High-dose chemotherapy with autologous hematopoietic cell transplant (auto-HCT) has been shown to improve survival in patients with newly diagnosed multiple myeloma. However, the role of salvage auto-HCT for relapsed patients, particularly in the era of novel therapeutics, is not well defined.

Methods: The authors performed a retrospective analysis of all 44 myeloma patients (24 men, 20 women) who received a second auto-HCT as salvage between January 3, 1992 and November 4, 2008 at The University of Texas MD Anderson Cancer Center.

Results: Median interval between the first and salvage auto-HCT was 30 months (range, 2-78 months). Median age at salvage HCT was 54 years (range, 38-73 years), and median number of salvage treatment regimens was 2 (range, 0-5). Eleven (25%) patients had high-risk chromosomal abnormalities on conventional cytogenetic studies between diagnosis and salvage auto-HCT. Ten patients (23%) experienced grade 3 or higher nonhematologic toxicity after the salvage auto-HCT. One patient died within 100 days, for a treatment-related mortality of 2%. Best responses after salvage chemotherapy + salvage auto-HCT were as follows: complete response (CR) + near CR, 11%; partial response, 79%; overall response rate, 90%. Eighteen (41%) patients received post auto-HCT maintenance therapy. Median follow-up from salvage HCT was 41 months. Kaplan-Meier estimates of median progression-free survival (PFS) and overall survival (OS) from time of salvage auto-HCT were 12.3 and 31.7 months, respectively. Median OS from the time of diagnosis was 75 months. In a fitted Bayesian multivariate model, shorter time to progression after first auto-HCT, greater number of prior therapies, African American race, and immunoglobulin G subtype were significantly associated with worse OS.

Conclusions: In selected myeloma patients, a second auto-HCT for salvage therapy is well tolerated, with acceptable toxicity. The overall response rate and PFS are comparable to other salvage regimens.