Algorithm for Administration of Plerixafor Pre-Apheresis for Adult Autologous Stem Cell Transplantation

Background:

The use of plerixafor can decrease the number of apheresis collection days for a given patient, which in turn reduces cost and other various resources. An algorithm was developed at our facility based on the paper published by LJ Costa in 2010 to predict the need for plerixafor on day four of G-CSF mobilization.

Methods:

Peripheral blood is drawn on day four of G-CSF mobilization (10µg/kg) for CD34 enumeration (pretube) using the single-platform ISHAGE method.  If the value is <14 CD34/µL for a single transplant or <25 CD34/µL for a tandem transplant the transplant recipient will receive plerixafor (0.24mg/kg).  If a patient does not qualify for plerixafor on the day previous to apheresis and does not collect all CD34/Kg required on day one they receive plerixafor for day two of apheresis.  This algorithm is used for all autologous transplant disease types treated at our facility (multiple myeloma, non-Hodgkin lymphoma, Hodgkin lymphoma, and germ cell) and is not adjusted for age, gender, performance status, etc. except under the direction of the medical director. Our targets for stem cell collection are 3.0x10⁶ CD34/Kg for a single transplant and 6.0x10⁶ CD34/Kg for tandem transplants.

Results:

From 2007-2009 we had a total of 110 apheresis collections (38 patients) for a single transplant with an average of 2.5 collection days per patient using G-CSF alone. 23.7% (n=9) of our patients collected in one day, 26.3% (n=10) collected in two days, and 50% (n=19) collected in three or more days. There were 28 tandem transplant collections (8 patients) with an average of 2.9 days of apheresis collection per patient. 12.5% (n=1) of our patients had one day of collection, 50% (n=4) had two days and 37.5% (n=3) had three or more days of apheresis. Plerixafor was first given in 01/2009 and until 07/2010 our patients received the drug based on insurance approval or as a second line of therapy after collection failure. Our algorithm was implemented starting 03/2011 and to date for a single transplant we have had 109 collections (67 patients) with an average of 1.7 days of collection per patient.  64% of patients (n=43) collected in one day, 25% (n=17) collected in two days and 10% (n=7) collected in three or more days.  There were 42 tandem transplant collections (30 patients) with an average of 1.5 days of apheresis collection per patient. 77% (n=23) of our patients collected in one day, 16.7% (n=5) collected in two days and 7% (n=2) collected in three or more days (see Figures 1 and 2).  There is a significant difference between the number of collection days needed for patients that received G-CSF alone and the collection days needed for patients evaluated with our algorithm (p<0.001).

Conclusion/Summary:

The addition of an algorithm for the use of plerixafor has significantly reduced the number of collections needed per patient, which in turn reduces cost and resources.