A commonly-used intensive induction regimen was associated with higher rates of hematopoietic progenitor cell mobilization failure in patients with mantle cell lymphoma, even when plerixafor rescue was attempted, based on a study by Amandeep Salhotra, MD, and his colleagues at City of Hope, Duarte, Calif.
Patients who received rituximab and hyperfractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone (R-hyperCVAD) in the era after plerixafor came into use experienced significantly higher rates of peripheral blood stem cell (PBSC) collection failure than did patients receiving other induction regimens (17% vs. 4% failure rate, P = .04).
Courtesy Wikimedia Commons/Nephron/Creative Commons
Intermediate magnification micrograph of mantle cell lymphoma of the terminal ileum.
“Plerixafor does not overcome the negative impact of R-hyperCVAD on PBSC mobilization, and caution is warranted in using R-hyperCVAD in patients with newly diagnosed MCL who are candidates for ASCT (autologous stem cell transplant),” wrote Dr. Salhotra and his colleagues.
The higher rate of hematopoietic progenitor cell collection failure for R-hyperCVAD patients could not be attributed to their age at time of mantle cell lymphoma diagnosis or to the amount of time between diagnosis and collection.
Treatment records for 181 consecutive mantle cell lymphoma patients were examined for a 10 year period in the retrospective single-site study. Plerixafor, a C-X-C chemokine receptor agonist that reduces hematopoietic progenitor cells’ ability to bind to bone marrow stroma, was introduced on August 16, 2009; a total of 71 patients were treated before this point, and 110 were treated afterward.
The R-hyperCVAD regimen was received by 34 pre-plerixafor patients (45%) and by 42 of the post-plerixafor era patients (55%). Other regimens were received by 37 (35%) and 68 (65%) of the pre- and post-plerixafor era patients, respectively.
Before plerixafor came into use, Dr. Salhotra, of City of Hope’s department of hematology and hematopoietic cell transplantation, and his coinvestigators saw no significant difference among their study population in the rates of PBSC collection failure between those receiving R-hyperCVAD (11%) and those receiving other regimens (12%). The findings were reported in Biology of Blood and Marrow Transplantation.
The study was conducted in the context of other recent work that showed higher rates of PBSC collection failure and fewer CD34+ cells collected with the use of an R-hyperCVAD conditioning regimen. The fact that PBSC mobilization rates were significantly lower in R-hyperCVAD patients post-plerixafor surprised the investigators, who had hypothesized that the use of plerixafor would overcome PBSC mobilization failures without regard to the conditioning regimen used.
“It may be worthwhile to consider using a more aggressive strategy for [hematopoetic progenitor cell] mobilization in patients who have received R-hyperCVAD chemotherapy upfront or as salvage for aggressive lymphomas,” the researchers wrote. This might include the use of plerixafor upfront when patients have low CD34 counts before apheresis.
The researchers plan to examine their data to see how the choice of induction regimen and plerixafor usage impact patient survival.
The study authors reported no conflicts of interest.
Source: Amandeep Salhotra, et al. Hyperfractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone chemotherapy in mantle cell lymphoma patients is associated with higher rates of hematopoietic progenitor cell mobilization failure despite plerixafor rescue. Biol Blood Marrow Transplant 2017; 23:1264-1268.
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SOURCE: Biol Blood Marrow Transplant 2017; 23:1264-1268. http://dx.doi.org/10.1016/j.bbmt.2017.04.011