Researchers found that the percentage of biosimilar uptake is a better predictor of whether prices of biologics will significantly decrease, refuting the argument that more biosimilars for a single reference product will have the biggest impact.
Researchers of a retrospective analysis found that the percentage of biosimilar uptake is a better predictor of whether prices of biologics will significantly decrease, refuting the argument that more biosimilars for a single reference product will have the biggest impact.
As more biosimilars enter the market, industry experts expect prices for biologics to decrease. However, a number of barriers have slowed down the number of biosimilars that are entering the market, especially in the rheumatology space. Payers often negotiate prices with manufacturers because of the high volume of per-patient spending on treatments for rheumatoid arthritis (RA) in the United States. As a result, insurance design is likely to impact treatment and costs associated with treatment in the future.
The authors of the study, which was published in the Journal of Medical Economics, used retrospective data to quantify the changes in price, utilization, and spending following the introduction of RA-specific therapies and to predict how these changes will manifest when adalimumab biosimilars enter the US market in 2023.
Data between December 1, 2013, and November 30, 2019, from IQVIA’s National Sales Perspective data set on exclusivity milestones was combined with data from the BioMed Informa Pharma Intelligence tracker to make predictions on price changes and market share due to biosimilar entry through 2025.
The results showed that for molecules that had a high biosimilar uptake (over 60%), such as epoetin alfa and filgrastim, prices fell a significant amount (21.2%-59.3% reductions). Molecules with a low amount of biosimilar uptake (under 10%), including infliximab and glatiramer acetate, experienced more moderate price decreases (2.4%-8.4% reductions).
The average price reduction after biosimilar entry on the investigators’ regression discontinuity design (RDD) estimation was 18.6% (P = .657) at the molecule level and 6.6% (P = .854) at the reference product level. Additionally, changes in average molecular prices were found to correlate with biosimilar uptake percentages.
The researchers estimated that the unitization market share of tumor necrosis factor inhibitors, including infliximab, was expected to decrease 24% between 2019 and 2025. When the RDD results were applied to adalimumab projected prices, the predicted share of total RA market spending decreased from 48% in 2019 to 26% to 2025. Furthermore, the reference adalimumab (Humira) is projected to lose 25,802 patients per year from 2019 to 2025.
The study had several limitations, including that the RDD approach did not account for off-label utilization of these molecules or other changes in market dynamics. The study used data from only the United States, meaning that the results should not be generalized to other global regions.
“Formulary placement, as well as manufacturer-payer dynamics, may play a role in determining price changes and market uptake of biosimilars. Future research should refine estimates as more biosimilars enter the US market,” the investigators wrote.
Hernandez EJM, Graf M, Portelli A, Shafrin J. Estimating the impact of biosimilar entry on prices and expenditures in rheumatoid arthritis: a case study of targeted immune modulators. J Med Econ. Published online August 15, 2022. doi:10.1080/13696998.2022.2113252