Two decades of pegfilgrastim: what have we learned? Where do we go from here?

Chemotherapy-induced febrile neutropenia (FN) is a medical emergency that may occur in patients with malignancies receiving myelosuppressive chemotherapy. FN requires early therapeutic intervention since it is associated with increased hospitalizations and high mortality risk of 5%-20%. FN-related hospitalizations are higher in patients with myeloid malignancies than in those with solid tumors due to the myelotoxicity of chemotherapy regimens and the compromised bone marrow function. FN increases the burden of cancer by causing chemotherapy dose reductions and delays. The administration of the first granulocyte colony-stimulating factor (G-CSF), filgrastim, reduced the incidence and duration of FN in patients undergoing chemotherapy. Filgrastim later evolved into pegfilgrastim, which has a longer half-life than filgrastim and was associated with a lower rate of severe neutropenia, chemotherapy dose reduction, and treatment delay. Nine million patients have received pegfilgrastim since its approval in early 2002. The pegfilgrastim on-body injector (OBI) is an innovative device facilitating the time-released auto-injection of pegfilgrastim approximately 27 hours after chemotherapy, as clinically recommended for the prevention of FN, thus eliminating the need for a next-day hospital visit. Since its introduction in 2015, one million patients with cancer have received pegfilgrastim using the OBI. Subsequently, the device has been approved in the United States (US), European Union, Latin America, and Japan, with studies and a postmarketing commitment demonstrating device reliability. A recent prospective observational study conducted in the US demonstrated that the OBI substantially improved the adherence to and compliance with clinically recommended pegfilgrastim therapy; patients receiving pegfilgrastim via the OBI experienced a lower incidence of FN than those receiving alternatives for FN prophylaxis. This review discusses the evolution of G-CSFs leading to the development of the OBI, current recommendations for G-CSF prophylaxis in the clinic, continued evidence supporting next-day pegfilgrastim administration, and improvements in patient care made possible with the OBI.

A prospective study to evaluate febrile neutropenia incidence in patients receiving pegfilgrastim on-body injector vs other choices

Purpose

We evaluated the incidence of febrile neutropenia (FN) and related clinical outcomes among patients treated with myelosuppressive chemotherapy for nonmyeloid malignancies who received pegfilgrastim on-body injector (OBI) or other options (Other) for FN prophylaxis.

Methods

In this prospective observational study, adult patients with breast, prostate, or lung cancer, or non-Hodgkin lymphoma at risk for FN were stratified into subgroups based on FN prophylaxis used in the first chemotherapy cycle: pegfilgrastim OBI vs Other (pegfilgrastim or biosimilar pegfilgrastim prefilled syringe, daily filgrastim, or no granulocyte colony–stimulating factor [G-CSF]) for up to 4 planned chemotherapy cycles.

Results

This US study enrolled 2575 eligible patients (OBI, 1624; Other, 951). FN incidence was lower in the OBI group (6.4% [95% CI, 5.2–7.6%]) than in the Other group (9.4% [7.5–11.2%]), with a relative risk (RR) of 0.66 (0.47–0.91; p = .006). A decreased risk of dose delays among patients receiving pegfilgrastim OBI vs Other was observed (RR for ≥ 5 days: 0.64 [0.42–0.96], p = .023; RR for ≥ 7 days: 0.62 [0.40–0.91], p = .016). Adherence, defined as G-CSF support for all chemotherapy cycles, was 94.0% (92.9–95.2%) in the OBI group compared with 58.4% (55.2–61.5%) in the Other group. Compliance with pegfilgrastim, defined as administration the day after chemotherapy, was 88.3% in the OBI group and 48.8% in the prefilled syringe group.

Conclusion

Patients receiving pegfilgrastim OBI had a lower incidence of FN compared with those receiving alternatives. The OBI was associated with improved adherence to and compliance with clinically recommended G-CSF prophylaxis.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00520-022-07226-9.