Contributions
Abstract: PB2440
Type: Publication Only
Background
The use of algorithms to administer PLX has increased the success rate of the PBSC mobilization treatments. However also the increase of the dose of G-CSF from 5 mcg/Kg to 10 mcg/Kg could be important to the end of harvesting an optimal amount of CD34+ cells. It is not known if “high dose G-CSF” and “on demand PLX” show a synergistic effect so that their combined used may be of additive usefulness or, on the contrary, if these two measures do not have a synergy.
Aims
Determine, in Multiple myeloma patients mobilized with cyclophosphamide 2-4 gr/sqm, if the use of high dose G-CSF (10 mcg/Kg) is more effective than lower dose (5 mcg/Kg) and if the possible increase of effectiveness of G-CSF high dose is influenced by the concomitant use of on demand Plerixafor.
Methods
404 patients were retrospectively studied, all were affected by MM and were in first mobilization attempt. All 404 patients received CTX at 2-4 gr/sqm, 180/404 patients were enrolled in on demand PLX (PLX GROUP) and 224/404 were not (NO PLX GROUP). In NO PLX GROUP 112 patients received G-CSF at 10 mcg/Kg and 68 received it at dose of 5 mcg/Kg. In PLX GROUP 153 received G-CSF at dose of 10 mcg/Kg and 71 at dose of 5 mcg/Kg.
Results
In NO PLX GROUP, percentage of patients failing to harvest the minimum CD34+ of 2x10e6/Kg was 19% in patients receiving 5 mcg/Kg versus 8.8% in patients receiving G-CSF at 10 mcg/Kg (p=0.04). Patients receiving G-CSF at dose of 5 mcg/Kg reached a harvest > 6x10e6 CD34+ cells in 42% of cases while this outcome was reached in 72% of patients receiving G-CSF at dose of 10 mcg/Kg (p=0.0001). Mean harvested CD34+ cells was 6.3 x10e6/Kg versus 13.0 x10e6/Kg (p=0.0001).
In PLX GROUP, patients failing the minimum CD34 harvest (2x10e6/Kg) was 5.0% and 1.7% in the two groups treated, respectively, with 5 mcg/Kg and in 10mcg/Kg (p=0.08) the optimal threshold of 6x10e6/Kg was reached In 67% of those receiving G-CSF at 5 mcg/Kg and in 73% of patients treated with G-CSF at 10 mcg/Kg (p=not significant). The mean number of harvested CD34+ cells was 10.4x10e6/Kg versus 11.2 x10e6/Kg, respectively in 5 mcg/Kg and in 10mcg/Kg groups (p=NS).
Thus, high dose G-CSF seems more advantageous when PLX on demand is not used while its efficacy is less evident when PLX on demand is programmed. We therefore wished to study the existence of an interaction between these two factors. In ANOVA test the amount of CD34 cells harvested was used as dependent variable and “dose of G-CSF” and “to be enrolled in a PLX ON DEMAND study” were evaluated. Interaction between the two factors was significant (F= 14.1; p=0.0002).
Conclusion
After CTX based mobilization, a dose of G-CSF of 10 mcg/Kg allows to reach an optimal amount of CD34+ cells (>6x10e6/Kg) more frequently in respect to the dose of 5 mcg/Kg. However, this hold true only when PLX is not used. In fact, in patients enrolled in PLX studies, there is no evidence that a higher dose of G-CSF determines further improvement in respect of that obtained with the use of the on demand PLX. Thus, we can conclude that if PLX on demand is used there is no need to increase dose of G-CSF.
Session topic: 23. Stem cell transplantation - Clinical
Keyword(s): Mobilization
Abstract: PB2440
Type: Publication Only
Background
The use of algorithms to administer PLX has increased the success rate of the PBSC mobilization treatments. However also the increase of the dose of G-CSF from 5 mcg/Kg to 10 mcg/Kg could be important to the end of harvesting an optimal amount of CD34+ cells. It is not known if “high dose G-CSF” and “on demand PLX” show a synergistic effect so that their combined used may be of additive usefulness or, on the contrary, if these two measures do not have a synergy.
Aims
Determine, in Multiple myeloma patients mobilized with cyclophosphamide 2-4 gr/sqm, if the use of high dose G-CSF (10 mcg/Kg) is more effective than lower dose (5 mcg/Kg) and if the possible increase of effectiveness of G-CSF high dose is influenced by the concomitant use of on demand Plerixafor.
Methods
404 patients were retrospectively studied, all were affected by MM and were in first mobilization attempt. All 404 patients received CTX at 2-4 gr/sqm, 180/404 patients were enrolled in on demand PLX (PLX GROUP) and 224/404 were not (NO PLX GROUP). In NO PLX GROUP 112 patients received G-CSF at 10 mcg/Kg and 68 received it at dose of 5 mcg/Kg. In PLX GROUP 153 received G-CSF at dose of 10 mcg/Kg and 71 at dose of 5 mcg/Kg.
Results
In NO PLX GROUP, percentage of patients failing to harvest the minimum CD34+ of 2x10e6/Kg was 19% in patients receiving 5 mcg/Kg versus 8.8% in patients receiving G-CSF at 10 mcg/Kg (p=0.04). Patients receiving G-CSF at dose of 5 mcg/Kg reached a harvest > 6x10e6 CD34+ cells in 42% of cases while this outcome was reached in 72% of patients receiving G-CSF at dose of 10 mcg/Kg (p=0.0001). Mean harvested CD34+ cells was 6.3 x10e6/Kg versus 13.0 x10e6/Kg (p=0.0001).
In PLX GROUP, patients failing the minimum CD34 harvest (2x10e6/Kg) was 5.0% and 1.7% in the two groups treated, respectively, with 5 mcg/Kg and in 10mcg/Kg (p=0.08) the optimal threshold of 6x10e6/Kg was reached In 67% of those receiving G-CSF at 5 mcg/Kg and in 73% of patients treated with G-CSF at 10 mcg/Kg (p=not significant). The mean number of harvested CD34+ cells was 10.4x10e6/Kg versus 11.2 x10e6/Kg, respectively in 5 mcg/Kg and in 10mcg/Kg groups (p=NS).
Thus, high dose G-CSF seems more advantageous when PLX on demand is not used while its efficacy is less evident when PLX on demand is programmed. We therefore wished to study the existence of an interaction between these two factors. In ANOVA test the amount of CD34 cells harvested was used as dependent variable and “dose of G-CSF” and “to be enrolled in a PLX ON DEMAND study” were evaluated. Interaction between the two factors was significant (F= 14.1; p=0.0002).
Conclusion
After CTX based mobilization, a dose of G-CSF of 10 mcg/Kg allows to reach an optimal amount of CD34+ cells (>6x10e6/Kg) more frequently in respect to the dose of 5 mcg/Kg. However, this hold true only when PLX is not used. In fact, in patients enrolled in PLX studies, there is no evidence that a higher dose of G-CSF determines further improvement in respect of that obtained with the use of the on demand PLX. Thus, we can conclude that if PLX on demand is used there is no need to increase dose of G-CSF.
Session topic: 23. Stem cell transplantation - Clinical
Keyword(s): Mobilization