Multiple Myeloma: Risk Adapted Use of Plerixafor for Stem Cell Mobilization Prior to Autologous Stem Cell...

We used plerixafor in 'a risk adapted approach' for stem cell mobilization for multiple myeloma (MM) patients prior to autologous stem cell transplantation (ASCT).

Between January, 2017 and December, 2019 105 consecutive patients of MM were recruited (Study Cohort). Patients received inj G-CSF 10 µg/kg in 2 divided doses for 5 days. Day 4 peripheral blood (PB) CD34+ count was used as a guide; if count was < 20 cells/µl, patients received plerixafor. For those with ≥ 20 cells/µl apheresis was commenced on day 5. We compared their outcome with 156 MM patients transplanted between 2012 and 2016 with G-CSF mobilized PB stem cells (Control Cohort). Primary end point was to collect ≥2.0  ×  10⁶ CD34+ cells/kg (minimal harvest). Secondary end points were: no of apheresis sessions, percentage of patients with optimal stem cell harvest (≥4.0  ×  10⁶ CD34+ cells/kg) and cost analysis. An intent to treat analysis was done.

96.2% of patients achieved ≥ 2.0  ×  10⁶ CD34+ cells/kg in the study cohort vs. 87.2% in the control cohort, P < .01. Mean apheresis sessions were 1.5 vs. 1.7 respectively, P < .014 . Optimal stem cell harvest was 29.5% vs. 16%,P = .23. Days for neutrophil engraftment (P < 0.025) and for IV antibiotics (P < .0017) were favorable for the study cohort. Incremental cost effectiveness ratio was $ 15.80/- and $ 10.56/- per 1% increase to achieve a minimal and optimal harvest.

Plerixafor in this risk adapted strategy resulted in successful mobilization, decreased time to engraftment and was cost effective.