Efficacy and Safety of Nivestim Versus Neupogen for Mobilization of Peripheral Blood Stem Cells for Autologous Stem Cell Transplantation

Comparison of biosimilar filgrastim and originator filgrastim for peripheral blood stem cell mobilization for allogeneic hematopoietic stem cell transplantation

BACKGROUND

Nivestym, a biosimilar granulocyte colony-stimulating factor (G-CSF) to the originator filgrastim (Neupogen), is now being used for the mobilization of peripheral blood stem cells (PBSC) in allogeneic hematopoietic stem cell transplantation (allo-HSCT). We aim to compare the efficacy of Nivestym and Neupogen for PBSC mobilization in healthy allogeneic donors.

METHODS

We conducted a retrospective single-center study including 541 adult allo-HSCT donors receiving Nivestym (January 2013-July 2020), or Neupogen (July 2020-June 2023) for donor PBSC mobilization. Bivariate analysis was conducted using SPSS version 28. Statistical significance was determined at a p-value <.05.

RESULTS

Our study included 541 allo-HSCT donors who received Neupogen (n = 345, 64%) or Nivestym (n = 196, 36%) for PBSC mobilization. The median age was 47 years (range 17-76). The median donor weight was 86 kg (95% confidence interval [CI]: 87-91). Donors receiving Neupogen had similar pre-G-CSF white blood cell count, CD34+ percentages, and circulating CD34+ count compared with donors receiving Nivestym. The Neupogen group had similar median PBSC product total neutrophil count, CD34+ percentage, absolute CD34+ count, and infused CD34+ dose compared with the Nivestym group. For donors aged 35 years or younger, the median CD34+ dose was higher in donors who received Neupogen compared with Nivestym (6.9 vs. 6.3 million cells/kg, p = .044).

CONCLUSIONS

Nivestym demonstrated similar efficacy for PBSC mobilization compared with Neupogen among allo-HSCT donors. In donors aged 35 years or younger, a slightly lower PBSC product CD34+ count was noted with Nivestym compared with Neupogen.

Safety of Marketed Cancer Supportive Care Biosimilars in the US: A Disproportionality Analysis Using the Food and Drug Administration Adverse Event Reporting System (FAERS) Database

BACKGROUND

Since the approval and availability of the first biosimilar in 2015 in the United States (US), evidence regarding the post-marketing safety of cancer supportive care biosimilars remains limited.

OBJECTIVE

The aim was to explore the adverse event (AE) reporting patterns and detect disproportionate reporting signals for cancer supportive care biosimilars in the US compared to their originator biologics.

METHODS

The US Food and Drug Administration Adverse Event Reporting System database (January 1, 2004-March 31, 2020) was used to identify AE reports for filgrastim, pegfilgrastim, and epoetin alpha by type of product (originator biologics vs. biosimilars) and report characteristics. Plots of AE reports against years were used to reveal the reporting patterns. Disproportionality analyses using reporting odds ratios (RORs) were conducted to detect differences in serious and specific AEs between studied drugs and all other drugs. Breslow-Day tests were used to determine homogeneity between the originator biologic-biosimilar pair RORs for the same AE.

RESULTS

Total numbers of AEs for all studied biosimilars increased after marketing. More AE reports were from female patients for all of the studied drugs. More AEs for originator biologics and filgrastim biosimilar were reported by health professionals, while the highest proportion of reports came from consumers for pegfilgrastim and epoetin alpha biosimilars (29% and 44.1%, respectively). Signals of disproportionate reporting in serious AEs were detected for a pegfilgrastim biosimilar (Fulphila^®) compared to its originator biologic.

CONCLUSION

Our findings support the similarity in the signals of disproportionate reporting between cancer supportive care originator biologics and biosimilars, except for Fulphila^®.