Since 2015, the US Food and Drug Administration (FDA) has approved 29 biosimilar products, with some biologics having between four and five biosimilars now available.
When FDA approved the country’s first biosimilar, Zarxio (filgrastim-sndz), the prospect that these products could help address the high cost of biologics and patient access issues seemed promising. However, the reality five years later is that uptake of biosimilars appears to be slow and inconsistent across medical specialties.
An article recently published on the Health Affairs blog by Alice J. Chen, PhD, associate professor at the University of Southern California (USC) Price School of Public Policy in Los Angeles, and colleagues points to insurance formularies as one explanation for slower uptake of biosimilars in the US. Having more than one biosimilar for a biologic may actually complicate matters for pharmacies, Chen and colleagues noted, because it can introduce coverage differences between insurers that issue formularies for which biosimilars they will reimburse. This is a change from how insurers handle reimbursement of a generic version of a small-molecule brand drug, Chen and colleagues said.
“Hospital providers can now face a dizzying set of rules that must be carefully tracked when treating patients with different insurers. If hospitals do not stock all versions preferred by their patients’ insurers, they may be required to custom order insurer-preferred drug requests or physicians may engage in non-medical switching, whereby a patient’s drug regimen is changed to follow payer formulary rules rather than clinical decision making,” they explained.
An example of how this might play out can be seen with the blood marrow stimulant pegfilgrastim. Chen and colleagues analyzed formulary notices for Neulasta, the originator biologic, and three biosimilars (Ziextenzo, Udenyca, and Fulphila) from Aetna, Cigna, United Healthcare, Anthem, and Blue Shield between October 2019 and March 2020. During this time, Chen and colleagues noted “[t]here was no consensus among insurers to prefer either the biologic or a biosimilar version” and these formulary preferences changed over time. “Taken together, these observations illustrate how payer-imposed formulary preferences add costs and complicate the work of hospital pharmacists and physicians,” they said.
Chen and colleagues advised a hospital pharmacy and therapeutics committee might be better suited to choose which version of a biologic or biosimilar should be used for patients, noting that “allowing hospitals to negotiate prices directly with manufacturers would ensure that competitive pressure continues to drive costs down, and that savings benefit patients and providers rather than supply-chain middlemen.”
Insurance formularies are not the only barriers to uptake of biosimilars. A recent paper published in the journal BioDrugs by Allison R. Kolbe, PhD, of the US Department of Health and Human Services (HHS) in Washington DC, and colleagues from HHS and FDA identified a hesitancy among healthcare professionals in dermatology, gastroenterology, hematology, oncology, nephrology and rheumatology to prescribe biosimilars.
Among 507 medical professionals surveyed (mean 51.4 years old, 71% male, 92.9% physicians), 13.5% respondents in dermatology, 51.5% in gastroenterology, 53.0% in nephrology, 81.0% in oncology/hematology, and 65.3% in rheumatology said they had previously prescribed a biosimilar. When their knowledge of biosimilars was tested, more than half of respondents said they were uncertain whether a hypothetical reference biologic and a second biosimilar product “had the same active ingredient, one or more of the same FDA-approved indications, common routes of administration, expected clinical performance, mechanism of action, and dosing,” and there was still uncertainty even among a majority of respondents with previous biosimilar prescribing experience.
In a prescribing scenario proposed to respondents of the survey administered by Kolbe and colleagues, a majority of respondents said they would choose to prescribe the hypothetical reference biologic over the biosimilar “when both drugs were available on formulary and chose the biosimilar product when only the biosimilar was available on formulary,” the authors said. Slightly more than half of respondents “indicated that they were likely or very likely to pursue a prior authorization for current patients successfully treated with the non-formulary reference product and who experience no tolerability issues,” they added. Almost half of respondents (48.5%) said their reason for not wanting to prescribe a biosimilar was because “they were waiting until biosimilar products have been on the market longer before prescribing them,” Kolbe and colleagues noted.
“Prescriber choice was highly influenced by formulary status, but prescribers identified numerous other influential factors, including confidence in pharmacovigilance and education on FDA approval processes,” they said. “Our results indicate that additional experience with biosimilars and improved education, starting with medical curricula through continuing education, will likely enhance prescribers’ understanding of these products, and may positively influence their willingness to prescribe biosimilars in the future.”
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