Study: Biosimilar Competition Did Not Consistently Lower Costs for Patients

Biosimilar competition did not consistently lower out-of-pocket costs for outpatients who were commercially insured, according to results of a study published in JAMA Health Forum. The investigators of the study said the results indicate the need for targeted policy interventions so that biosimilar competition can increase cost savings and affordability for patients.

According to the study authors, biosimilar costs can range from 15% to 25% lower than their brand-name reference product, which can result in manufacturers lowering prices or offering discounts. However, it has not been clear whether biosimilar competition lowers the cost for patients using biologics. Investigators of the study assessed the out-of-pocket costs for those who are commercially insured across 7 physician-administered biologics with a biosimilar available in the United States as of January 2021, according to the stud investigators. They aimed to determine whether the annual out-of-pocket costs decreased after biosimilar competition and whether patients using biosimilar had lower out-of-pocket costs compared to patients using the brand name product.

Investigators used claims from January 1, 2009, through March 31, 2022, for adults aged younger than 65 years with commercial insurance plans. The primary outcome included out-of-pocket cost for the patient, which included deductible, copayment, and coinsurance, according to the study authors. The biosimilar competition included market competition between November 2013, including filgrastim, and July 2019, including trastuzumab.

Biosimilars included were approved for cancers, hematology, inflammation disorders, and autoimmune disorders, according to the study authors. As of analysis in January 2021, epoetin alfa had 1 biosimilar and the other reference products had at least 2 biosimilars ranging to 5 for trastuzumab. A total of 1.7 million claims were analyzed from 190,364 individuals.

In the first analysis for the trends in annual out-of-pocket cost, investigators used a total of 1.3 claims in the first 4 years before and after biosimilar competition for each drug. However, only filgrastim and infliximab had the full 4 years of post-competition data. For other biosimilars, at least 2 years of data were included. Infliximab was the most common biologic prescribed at 31% of patient-years and epoetin alfa only made up 3% of patient years, according to the study authors.

For approximately 49% of patient-years, patients had an annual out-of-pocket spending of above 0, averaging all 7 drugs, patients with nonzero out-of-pocket costs were greater both before and after biosimilars entered the market. Further, investigators found that patients had a higher mean nonzero annual out-of-pocket cost both before and after biosimilar competition.

Two biologics (rituximab and trastuzumab) were the only drugs that showed significantly lower mean nonzero annual out-of-pocket spending after 2 years of biosimilar competition, according to the study authors. The other drugs were either higher or did not have significant changes.

In the second analysis for out-of-pocket costs for biosimilars compared to the reference product, investigators included 586,493 claims for any of the 7 biologics after biosimilars were available. Approximately 25% were a biosimilar, according to the study authors. Overall, investigators found that 28% of the reference biologic claims and 17% of biosimilars has nonzero out-of-pocket costs, but after adjustment, biosimilars were more likely to have nonzero out-of-pocket claims compared to the reference product. The study authors added that there was variation among the 7 drugs, with some claims for the biosimilar more likely to have nonzero out-of-pocket costs (infliximab) and some where the reference product was more likely to have nonzero out-of-pocket claims (bevacizumab).

Furthermore, investigators found that the mean out-of-pocket costs were lower for biosimilars at $707 compared to the reference product at $911, according to the study authors.

Reference

Feng K, Russo M, Maini L, Kesselheim AS, Rome BN. Patient Out-of-Pocket Costs for Biologic Drugs After Biosimilar Competition. JAMA Health Forum. 2024;5(3):e235429. doi:10.1001/jamahealthforum.2023.5429