Using Biosimilar Filgrastim May Lead to Shorter Hospitalization, Lower Cost in PBSC Mobilization

In autologous stem cell transplantation, mobilization of peripheral blood stem cells (PBSCs) is crucial, and the use of granulocyte colony-stimulating factor (G-CSF) therapies plays a key role in ensuring success. Lower-cost biosimilar G-CSF agents may be a way to reduce the overall cost of treatment, and in a recent study in a single center in Singapore, researchers found that a biosimilar filgrastim, Pfizer’s Nivestim (sold in the US market as Nivestym), was safe and noninferior to its reference, Neupogen, in mobilizing stem cells for autologous stem cell transplantation.

In the study, all patients who underwent autologous stem cell transplantation between 2011 and 2016 were included in the retrospective cohort. Those treated up to March 2014 (n = 66) had received the reference filgrastim, while those treated afterward received the biosimilar (n = 65). Patient characteristics were similar with the exception of chemo-mobilization regimen.

The primary outcome of the study was the proportion of patients who had successful mobilization, which was defined as a harvest of at least 2 × 10⁶ CD34⁺ cells per kilogram of bodyweight.

In the biosimilar group and the reference group, mobilization was successful in 96.9% and 97% of patients, respectively (P = .988). The authors noted that the number of CD34+ cells mobilized was higher in the biosimilar group, although the difference did not achieve statistical significance. Safety was also similar; the incidence and severity of adverse events were comparable between the groups, with headache, back pain, and bone pain being the most commonly reported.

Notably, the median length of hospital stay required for mobilization was significantly shorter in the biosimilar group (15 days) than in the reference group (17 days), and the duration of G-CSF use per mobilization was lower in the biosimilar group (9 days) than in the reference group (10 days).

Using the biosimilar also resulted in a significantly lower drug acquisition cost, at $533.40 in the biosimilar group versus $1261.90 in the reference group (P <.0001).

According to the authors, using the biosimilar to mobilize stem cells was both safe and noninferior to using the reference filgrastim, and results in a lower drug cost and a potentially shorter length of hospitalization.

Reference

Chew C, Ng HY. Efficacy and safety of Nivestim versus Neupogen for mobilization of peripheral blood stem cells for autologous stem cell transplantation [published online December 27, 2019]. Sci Rep. 2019. doi: 10.1038/s41598-019-56477-w.