When providers get used to biosimilars, they tend to prescribe them exclusively, according to a study in The American Journal of Managed Care.
Once physicians are comfortable with biosimilar use, they tend to adopt biosimilars exclusively, discontinuing any use of the reference biologic, according to the authors of a study of factors associated with biosimilar use.
The same study, published in The American Journal of Managed Care, demonstrated that providers were more likely to prescribe biosimilars for patients under financial constraint, such as younger patients who do not qualify for Medicare coverage or nonwhite patients with lower incomes.
Health maintenance organization cost capitation rules also play a role in providers’ tendency to prescribe biosimilars.
Interestingly, the investigators found that biosimilar uptake was higher in provider office-based clinics versus hospitals, which they said was consistent with literature that documents higher cancer-related costs in hospital settings due to higher product costs.
Financial Incentives Skew Uptake
One reason suggested for the hospital tendency to use higher cost drugs was that hospital providers are incentivized differently. They are more likely to be paid a percentage of hospital charges, and if reference biologics are more costly than biosimilars, they are more likely to be prescribed.
Ironically, the structure of the 340B Drug Pricing Program, which is designed to make costly medicine more accessible in areas of need, may contribute to the hospital tendency to buy more costly drugs, the investigators said. Based on these factors, the authors concluded, provider awareness and incentives “can be important levers to increase biosimilar market penetration.”
“Although frustrations over the slow pace of biosimilar introduction and adoption in the United States have led some to abandon hope that a competitive biosimilar market will produce lower prices, our study findings underscore the need for additional research on the mechanisms of uptake as promising policy targets to strengthen competition in US biosimilar markets,” the authors wrote.
Biosimilars are considered an important means of lowering medicine costs because biologics account for a significant share of overall prescription drug spending: 38% in 2015, the authors noted. Biosimilars, which are clinically equivalent to the reference drug products they imitate, represent potential savings because they compete with reference drugs and typically launch at a discount.
There are currently 26 biosimilars approved and 16 on the market in the United States.
The authors did a close study of the uptake of Zarxio, the biosimilar filgrastim to reference Neupogen. Zarxio was launched in September 2015, and by the 3-year point, the share of reimbursement claims for Zarxio versus Neupogen was 60% among office-based providers and 49% among providers at outpatient hospitals.
Uptake Began Before Significant Price Cuts
The authors noted that providers began adopting the filgrastim biosimilar before any significant reduction occurred in cost. By mid-2018 the average sales price for the biosimilar had fallen to 67% of the biologic’s ASP. This adoption trend was noted mainly among office-based providers; the hospital-based provider adoption trend more closely mirrored reductions in ASP, the authors wrote. Further, “as office-based adoption rates have continued to rise, adoption rates in the hospital setting have plateaued at around 50%.”
This observation was a clue that factors besides price play a role in the uptake of biosimilars in hospital settings, the authors concluded.
Another observation was that providers tended to prescribe the biosimilar to all patients or they used the reference brand exclusively. There was very little middle ground where prescribers prescribed both reference and biosimilar products.
“By quarter 2 of 2018, approximately 61% (742 of 1223) of providers were offering some Zarxio; of this group, 88% (651 of 742) were offering exclusively Zarxio,” The authors wrote. Just 91 providers were administering both biosimilar and reference product, and 481 were administering only the originator brand. The pattern was evident across hospital- and office-based providers.
Office based providers were 22% more likely than hospital-based providers to have adopted the biosimilar version of filgrastim.
Chen AJ, Ribero R, Van Nuys K. Provider differences in biosimilar uptake in the filgrastim market [published online ahead of print March 25, 2020]. Am J Manag Care. 2020;26(5). www.ajmc.com/journals/issue/2020/2020-vol26-n5/provider-differences-in-biosimilar-uptake-in-the-filgrastim-market.