United States Still Lags Behind Other Nations in Adopting Biosimilar Filgrastim

Since the advent of biosimilar filgrastim, patient access to the prophylaxis of chemotherapy-induced febrile neutropenia (FN) has improved in many regulatory territories, yet concerns remain about whether the United States is keeping pace with the rest of the world in biosimilar uptake and associated patient access.

A recent study in BMC Cancer examined the use of biosimilar filgrastim, Zarzio (sold as Zarxio in the United States), in Europe, and found that prescribing of biosimilar filgrastim is now generally in line with European Organisation for Research and Treatment of Cancer guidelines for the prophylaxis of FN.¹

However, in the United States, research has demonstrated that continued underutilization of filgrastim—whether reference or biosimilar—is associated with serious consequences for patient health and healthcare costs. One recent study found that hospital costs represented the largest proportion of total medical costs for patients who developed neutropenia and required inpatient care, and that, in a cohort of 3459 Medicare Advantage beneficiaries undergoing chemotherapy, neutropenia-related medical costs reached $21,733 (standard deviation, $30,003) for patients who had neutropenia with infection and fever.²

Given the clear need for FN prophylaxis to protect patient health and reduce costs for cancer care, why does the United States lag behind other regulatory territories in terms of using cost-saving biosimilar filgrastim? This month, authors Zaina P. Qureshi, PhD, MPH, MS; Sumimasa Nagai, MD; and Charles L. Bennett, MD, PhD, MPP, addressed this question in a viewpoint article published in JAMA Oncology.³

According to the authors, the ability of pharmacists to substitute an interchangeable product with its reference may increase biosimilar competition in the United States to the levels seen in the European Union and Japan, though they acknowledge that there is as-yet no interchangeable biosimilar in the US market. Another key factor that drives down costs in Japan is a mandatory price discount of approximately 30% that is mandated for Japanese biosimilars, versus approximate 15% voluntary price discounts seen for US biosimilar filgrastim.

Additionally, patent litigation in the United States far outpaces such legal challenges in Europe and Japan. According to the authors, no patent suits were filed by the maker of the reference filgrastim in the 28 EU member states or in Japan after the introduction of biosimilar filgrastim, though such challenges resulted in launch delays in the United States. Furthermore, the complex system of rebates in the US context can result in lower prices for reference biologics than biosimilars, despite biosimilars’ lower list prices.

Looking to the future, write the authors, the launch of additional biosimilar will spur price competition, and physician and patient educational efforts should emphasize the benefits of biosimilar adoption for the healthcare system. Finally, legislators should demand greater transparency and accountability concerning rebates provided by drug makers.

References

1. Roché H, Eymard JC, Radji A, et al. Biosimilar filgrastim treatment patterns and prevention of febrile neutropenia: a prospective multicentre study in France in patients with solid tumours (the ZOHé study). BMC Cancer. 2018;18:1127. doi: 10.1186/s12885-018-4986-1.

2. Schartzberg LS, Lal LS, Balu S, et al. Clinical outcomes of treatment with filgrastim versus a filgrastim biosimilar and febrile neutropenia—associated costs among patients with nonmyeloid cancer undergoing chemotherapy [published online April 24, 2018]. J Manag Care Spec Pharm. doi: 10.18553/jmcp.2018.17447.

3. Qureshi ZP, Nagai S, Bennett CL. Biosimilar filgrastim use in the United States vs the European Union and Japan—why does it lag behind and what can be done? [published online December 3, 2018]. JAMA Oncology. doi: 10.1001/jamaoncol.2018.5636.