Third time's a charm? Mobilization of autologous peripheral blood stem cells in patients with two previous failed mobilizations with plerixafor

Comparison of the efficacy of a generic plerixafor versus Mozobil as adjunct peripheral blood stem cell mobilization agents in multiple myeloma patients

BACKGROUND

Plerixafor is an adjunct peripheral blood stem cell (PBSC) mobilization agent with well-demonstrated safety and efficacy. The routine use of the originator brand drug (Mozobil) has been limited by cost. This retrospective study was conducted to compare the mobilization efficacy of a lower-cost generic plerixafor and Mozobil in multiple myeloma (MM) patients.

STUDY DESIGN AND METHODS

The study included two near-concurrent cohorts of MM patients mobilized with brand (n = 64) or generic (n = 61) plerixafor in addition to filgrastim. Collection and early engraftment outcomes were compared.

RESULTS

The two cohorts had comparable distributions of sex, age, and weight. Previous treatment histories and proportions of upfront versus just-in-time plerixafor use were similar. There was no significant difference in their median overall cumulative total yield (106 CD34+ cells/kg) (brand, 5.91; generic, 5.80; p = .51). However, the generic cohort had a significantly higher median yield after the first dose (4.79 vs. 3.78, p = .03), and consequently lower median numbers of plerixafor doses (p = .001) and collection days (p = .002). Only 31.1% of patients in the generic arm required more than one dose versus 59.4% of patients in the brand arm (p = .006). All transplanted patients in the brand and generic arms (90.6% and 85.2% respectively, p = .42) achieved engraftment. There was no significant difference in their median times to platelet and neutrophil engraftment, nor their transfusion requirements during the first 30 days post-transplant.

CONCLUSION

The generic plerixafor produced comparable cumulative collection yields and early engraftment outcomes as Mozobil, but fewer doses and collection days were needed to reach collection goal.

Addition of plerixafor to G-CSF in poor mobilizing healthy related donors overcame mobilization failure: An observational case series on behalf of the Grupo Español de Trasplante Hematopoyético (GETH)

Plerixafor (Mozobil, Sanofi) is approved for using in patients with lymphoma and multiple myeloma when steady-state mobilization strategies fail. Although off-label use of plerixafor in healthy related donors (HRD) is known, limited data are available and no recommendations exist to guide its use in this setting. With the aim of collecting data from HRDs who received plerixafor in our country, we designed an observational case series study within the Spanish Group of Hematopoietic Transplant and Cell Therapy (GETH). Plerixafor was administered subcutaneously to 30 HRDs at a median dose of 0.24 mg/Kg (interquartile range (IQR): 0.23-0.25) because mobilization failure after using mobilization with G-CSF (mobilization failure was defined as collection of <4.0 × 10⁶ CD34+ cells/Kg recipient). All HRDs received G-CSF at a median dose of 11 μg/Kg/day (IQR: 10-12) for 4-5 days. Leukocytapheresis after G-CSF mobilization was performed in 23 (77 %) HRDs collecting a median of 1.6 × 10⁶ CD34+ cells/Kg recipient weight (IQR: 0.9-2.5). Addition of plerixafor allowed the collection of a higher median number of CD34 cells (4.98 × 10⁶ CD34+ cells/Kg recipient weight (IQR: 3.5-5.8)) when compared with the collection of CD34+ cells with G-CSF alone (p < 0.01). The final median total number of CD34+ cells collected was 6.1 × 10⁶/Kg recipient weight (IQR: 4.8-7.3). Mild adverse events related with plerixafor administration were reported in 8 (27 %) donors. In conclusion, addition of plerixafor after G-CSF mobilization failure in HRDs allowed collecting higher number of CD34+ cells in comparison with steady-state mobilization.