Contributions
Type: Publication Only
Background
Over the past 10 years, novel agents (NA), including immunomodulatory drugs and proteasome inhibitors, have been increasingly incorporated in front line multiple myeloma (MM) treatment. Induction with NA did not negatively affected the efficacy of stem cell harvest in some studies. Few data are available on the prognostic role of residual bone marrow plasma cells (BMPC) assessment on peripheral blood stem cell harvest after induction therapy with NA in MM patients undergoing autologous stem cell transplant (ASCT).
Aims
The aim of this retrospective single-center study was to determine the impact of BMPC, quantified before peripheral blood stem cell (PBSC) mobilization, on the efficacy of CD34+ cells collection and number of leukapheresis.
Methods
This retrospective study concerned 132 newly diagnosed MM patients who underwent ASCT in the Hematology Unit in Florence from January 2006 to January 2015. Induction therapy included dexamethasone with thalidomide (TD) and/or bortezomib (VTD, VD). Patients who were refractory to induction therapy were excluded from the study. Bone marrow biopsy was performed before PBSC mobilization and residual plasma cells were evaluated after CD138, kappa and lambda immunostaining. All patients were mobilized with cyclophosphamide (EDX) 3 or 4 gr/m2 followed by G-CSF 5-10 μg/kg daily subcutaneously from day 2 until the end of the collection procedure. Leukapheresis was scheduled to start on day 10 and be performed until at least 2.0×106 CD34+ cells/kg were collected. Patients who failed G-CSF mobilization received plerixafor. CD34+ cells counts were assayed using a single platform method. Statistical analisys was made by Mann-Whiney test.
Results
Median age was 59 (range, 37-68), 48 patients (37%) were females; 81 patients (61%) received VTD as induction therapy (3-7 cycles) while 39 (30%) received TD (3-8 cycles) and 12 (9%) received VD (4-6 cycles). After induction therapy 18 (14%) patients obtained a complete response, 62 (47%) had a very good partial response, 49 (37%) a partial response, and 3 (2%) a minimal response. BM biopsy was performed in all patients: in 67 (51%) the BMPC were <5% of the total cellularity, whereas in 40 (30%) the BMPC were between 5% and 20% and in 25 (19%) the BMPC were over 20%. All patients proceeded to chemo-mobilization: 16 (12%) with EDX 3 gr/m2 and 116 (88%) with EDX 4 gr/m2. No grade ≥3 toxicities were recorded. In 98 patients (74%), the mean number of CD34+ cells collected was 12.2×106/kg (range 2.8-57.2x106/kg) within 1 leukapheresis; 23 (17%) patients needed a second procedure to collect a mean CD34+ cells count of 7.3×106/kg (range, 2.0-16.2x106/kg), whereas 7 patients (5%) required 3 or 4 procedures and collected 4.4×106/kg (range, 2.3-7.4x106/kg) (p=ns). A total of 4 (3%) patients, all females, aged 49-61 years (median age 60 years), received plerixafor. In 2 patients, the mean number of CD34+ cells was 5.8 x106/kg collected in 1 day, in 2 other patients leukapheresis was repeated 3 times to collect 6.9x106 cells/kg. The BMPC percentage was not significantly correlated with the mean CD34+ cells counts or with the numbers of leukapheresis. The CD34+ cells count was significantly higher in patients younger than 55 (n=47; mean 12.7×106/kg, range 4.9-36.8) than in the older patients (n=85; mean 9.6×106/kg, range 2.0-57.2) (p<0.001). Furthermore the mean CD34+ cells count was significantly higher in patients treated with VTD (n=81; mean 11.8×106/kg, range 2.7-57.2) vs those treated with TD (n=39; mean 8.2× 106/Kg, range 2.0-21.2).
Summary
The residual BMPC percentage did not adversely impact on CD34+ collection in our study. Younger age and VTD induction were associated with higher CD34+ cells counts.
Keyword(s): Autologous peripheral blood stem cell tansplantati, Autologous stem cell collection, Mobilization, Multiple myeloma
Session topic: Publication Only
Type: Publication Only
Background
Over the past 10 years, novel agents (NA), including immunomodulatory drugs and proteasome inhibitors, have been increasingly incorporated in front line multiple myeloma (MM) treatment. Induction with NA did not negatively affected the efficacy of stem cell harvest in some studies. Few data are available on the prognostic role of residual bone marrow plasma cells (BMPC) assessment on peripheral blood stem cell harvest after induction therapy with NA in MM patients undergoing autologous stem cell transplant (ASCT).
Aims
The aim of this retrospective single-center study was to determine the impact of BMPC, quantified before peripheral blood stem cell (PBSC) mobilization, on the efficacy of CD34+ cells collection and number of leukapheresis.
Methods
This retrospective study concerned 132 newly diagnosed MM patients who underwent ASCT in the Hematology Unit in Florence from January 2006 to January 2015. Induction therapy included dexamethasone with thalidomide (TD) and/or bortezomib (VTD, VD). Patients who were refractory to induction therapy were excluded from the study. Bone marrow biopsy was performed before PBSC mobilization and residual plasma cells were evaluated after CD138, kappa and lambda immunostaining. All patients were mobilized with cyclophosphamide (EDX) 3 or 4 gr/m2 followed by G-CSF 5-10 μg/kg daily subcutaneously from day 2 until the end of the collection procedure. Leukapheresis was scheduled to start on day 10 and be performed until at least 2.0×106 CD34+ cells/kg were collected. Patients who failed G-CSF mobilization received plerixafor. CD34+ cells counts were assayed using a single platform method. Statistical analisys was made by Mann-Whiney test.
Results
Median age was 59 (range, 37-68), 48 patients (37%) were females; 81 patients (61%) received VTD as induction therapy (3-7 cycles) while 39 (30%) received TD (3-8 cycles) and 12 (9%) received VD (4-6 cycles). After induction therapy 18 (14%) patients obtained a complete response, 62 (47%) had a very good partial response, 49 (37%) a partial response, and 3 (2%) a minimal response. BM biopsy was performed in all patients: in 67 (51%) the BMPC were <5% of the total cellularity, whereas in 40 (30%) the BMPC were between 5% and 20% and in 25 (19%) the BMPC were over 20%. All patients proceeded to chemo-mobilization: 16 (12%) with EDX 3 gr/m2 and 116 (88%) with EDX 4 gr/m2. No grade ≥3 toxicities were recorded. In 98 patients (74%), the mean number of CD34+ cells collected was 12.2×106/kg (range 2.8-57.2x106/kg) within 1 leukapheresis; 23 (17%) patients needed a second procedure to collect a mean CD34+ cells count of 7.3×106/kg (range, 2.0-16.2x106/kg), whereas 7 patients (5%) required 3 or 4 procedures and collected 4.4×106/kg (range, 2.3-7.4x106/kg) (p=ns). A total of 4 (3%) patients, all females, aged 49-61 years (median age 60 years), received plerixafor. In 2 patients, the mean number of CD34+ cells was 5.8 x106/kg collected in 1 day, in 2 other patients leukapheresis was repeated 3 times to collect 6.9x106 cells/kg. The BMPC percentage was not significantly correlated with the mean CD34+ cells counts or with the numbers of leukapheresis. The CD34+ cells count was significantly higher in patients younger than 55 (n=47; mean 12.7×106/kg, range 4.9-36.8) than in the older patients (n=85; mean 9.6×106/kg, range 2.0-57.2) (p<0.001). Furthermore the mean CD34+ cells count was significantly higher in patients treated with VTD (n=81; mean 11.8×106/kg, range 2.7-57.2) vs those treated with TD (n=39; mean 8.2× 106/Kg, range 2.0-21.2).
Summary
The residual BMPC percentage did not adversely impact on CD34+ collection in our study. Younger age and VTD induction were associated with higher CD34+ cells counts.
Keyword(s): Autologous peripheral blood stem cell tansplantati, Autologous stem cell collection, Mobilization, Multiple myeloma
Session topic: Publication Only