Researchers Present Findings on Patient Preferences, Outcomes With G-CSFs

The use of granulocyte colony-stimulating factor (G-CSF) therapies is well understood to decrease the incidence of febrile neutropenia (FN), a serious adverse event related to myelosuppressive chemotherapy. Multiple G-CSF options are available to prevent FN, including reference and biosimilar filgrastim and pegfilgrastim products.

During this week’s meeting of the International Society for Pharmacoeconomic and Outcomes Research, held from May 18 to 22 in New Orleans, Louisiana, researchers presented findings on both patient attitudes toward these drugs and the drugs’ effectiveness in the prophylaxis of FN.

One research team presented a study that found that patients preferred—and were willing to pay for—G-CSFs that were convenient and provided improved clinical outcomes.¹

The study’s authors created a discrete-choice experiment that used an online cross-sectional survey of self-reported patients with breast cancer who had previously received myelosuppressive chemotherapy.

The 302 participants were presented with 18 scenarios with different levels of multiple attributes, including the risk of developing FN that required hospitalization, the risk of disrupting chemotherapy, the need for additional clinic visits, the number of G-CSF administrations, and total out-of-pocket costs for G-CSF.

They found that participants preferred the options with the lowest out-of-pocket costs, followed by the lowest risk of FN that required hospitalization, the lowest risk of chemotherapy disruption, a lower number of clinic visits, and fewer administrations.

Median incremental willingness to pay was $948 to reduce the risk of being hospitalized for FN, and $420 to reduce the number of additional visits to the clinic.

Some subgroups, including those from the Midwest, those covered by Medicare Part D, and those with experience with an on-body injector device, valued convenience more highly than other groups.

A second research team reported that that patients with high—FN risk chemotherapy regimens gained the most benefit from G-CSF therapy.²

Using a commercial, deidentified paid claims dataset from 2007 to 2016, the researchers used diagnostic codes to identify patients with breast cancer, to document the occurrence of FN, and to locate chemotherapy and G-CSF claims. A logistic regression model was used to estimate the association between patient and chemotherapy regimen characteristics and the use of G-CSF.

Patients who used G-CSF were less likely to experience FN (hazard ratio [HR], 0.24; P <.01) and death within 60 days of chemotherapy (HR, 0.22; P <.01) during their first cycle than those who did not use G-CSF.

The effects of G-CSF were particularly substantial for those who had high-risk chemotherapy regimens (HR, 0.19; P <.01). However, no significant association was found between the timing of prophylaxis and its effectiveness in reducing FN risk.

References

1. Yucel A, Chase K, Kumar R, Fuehrer D, Bensink M. Breast cancer patient preference and willingness to pay for granulocyte colony-stimulating factors (G-CSF). Presented at: International Society for Pharmacoeconomics and Outcomes Research 24th Annual International Meeting; May 18-22, 2019; New Orleans, Louisiana. Abstract PCN265.

2. Lee CH, Mccombs J. An analysis of granulocyte-colony stimulation factor utilization for the prevention of chemotherapy-induced febrile neutropenia among breast cancer patients in the United States. Presented at: International Society for Pharmacoeconomics and Outcomes Research 24th Annual International Meeting; May 18-22, 2019; New Orleans, Louisiana. Abstract PCN15.