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.