Abstract
Background: Autologous stem cell transplantation (ASCT) is standard therapy for patients with multiple myeloma (MM). Stem cell mobilization for peripheral blood stem cell collection prior to ASCT is most commonly achieved with cyclophosphamide based chemotherapy regimens and GCSF (Cy-G) or with plerixafor and GCSF (Pler-G). Using a chemotherapy based mobilization regimen for patients with lymphoma has been shown to result in higher CD34+ cell yield and lower cost than plerixafor based regimens (Dhakal, et al. 2016). The question remains if stem cell mobilization regimens impact stem cell collection and ASCT outcomes in patients with MM.
Methods: We reviewed 496 patients who received 596 ASCT for MM between January 2005 and December 2015. Data analyzed included stem cell mobilization regimen, number of CD34+ cells collected, number of apheresis procedures, CD34+ cells infused and survival. Univariate and Multivariate Cox Proportional Regression Models were utilized. The purpose of the review was to determine outcome differences between the use of Cy-G for stem cell mobilization vs Pler-G.
Results: The median age at transplantation was 61 years (range 39-84) and 59% were male. Cy-G was used for stem cell mobilization for 438 patients (91%) vs 44 patients (9%) who received Pler-G. Significantly greater numbers of CD34+ cells were collected using Cy-G, with a median of 16.17 x 10e6/kg vs a median of 12.47 x 10e6/kg with Pler-G (p=0.0012). Median days of collection were less for Cy-G, 2 vs 3 for Pler-G (p=0.292), although not significant. There was no statistical difference in the dose of CD34+ cells infused, with a median of 5.73 x 10e6/kg for Cy-G vs a median of 5.00 x 10e6/kg for Pler-G. Pre-ASCT therapy using immunomodulatory agents lenalidomide, bortezomib or carfilzomib had no impact on the number of CD34+ cells collected (p=0.3427), number of apheresis procedures (p=0.6336) or CD34+ cell dose infused (p=0.941).
OS at 84 months was 58% for patients using Cy-G for stem cell mobilization vs 55% for patients using Pler-G (p=0.9168) indicating no difference. By multivariate analysis, there was no difference in OS between the 2 groups (p=0.488). There was no difference in PFS between the 2 stem cell mobilization regimens by univariate or multivariate analysis (p=0.2737 and p=0.4226). There was no statistical difference (p=0.424) in the incidence of engraftment syndrome based on the stem cell mobilization regimen.
Conclusion: For patients with MM, using a Cy-G regimen results in a higher CD34+ cell yield compared to Pler-G. Higher CD 34+ cell yield may be advantageous for patients considering tandem autologous transplantation. Pre-transplant therapy with immunomodulatory agents had no significant impact on CD34+ cell yield or apheresis days. There was no difference in OS or PFS between the 2 groups and no difference in the incidence of engraftment syndrome. The medication cost at our institution for a 70 kg patient receiving cyclophosphamide, dexamethasone and etoposide with GCSF is $8,846.64 compared to $24,846.09 for Pler-G. Cyclophosphamide based regimens for stem cell mobilization results in a higher cell yield with lower cost and equal survival compared to Pler-G in patients with MM.
McKiernan: Novartis: Speakers Bureau. Siegel: Celgene, Takeda, Amgen Inc, Novartis and BMS: Consultancy, Speakers Bureau; Merck: Consultancy. Vesole: Takeda: Speakers Bureau; Celgene: Speakers Bureau. Skarbnik: Genentech: Speakers Bureau; Seattle Genetics: Speakers Bureau; Novartis: Speakers Bureau; Abbvie: Other: Ad board, Speakers Bureau; Gilead: Speakers Bureau. Biran: Celgene, Amgen: Consultancy, Speakers Bureau; Takeda: Speakers Bureau. Richter: Amgen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; BMS: Speakers Bureau; Janssen: Speakers Bureau; Takeda: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Pecora: Caladrius Biosciences: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; COTA: Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties. Goy: Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pharmacyclics / J&J: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Seattle Genetics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Acerta: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Genentech: Research Funding. Pereiras: Portola Pharmaceutical: Other: stock holder; TEVA: Consultancy.
