Biologic drugs play an important role in treating cancers such as breast cancer and lymphoma, but their high costs can add to the financial burden of cancer care. Now, lower-cost versions known as biosimilars are gaining ground, and a new study led by researchers at the UCLA Health Jonsson Comprehensive Cancer Center suggests their growing use is associated with lower costs for both insurers and patients.
The findings, published in JAMA Oncology, show that patients with cancer who exclusively used biosimilars had average monthly costs that were $3,820 lower for insurers and $39.50 lower out of pocket compared with patients who exclusively used the original branded biologic drugs. The results provide evidence that market competition enabled by entry of biosimilars may help reduce the cost of cancer biologic drugs.
Why it matters
Cancer treatment can place a significant financial burden on patients, with financial hardship associated with medication nonadherence and poorer health outcomes. The high and rising cost of anticancer medications, particularly biologic drugs, which are complex medicines made using living cells, is one contributor to this burden. Previous research has estimated that financial toxicity may affect as many as half of patients with cancer in the United States.
Biosimilars were introduced as one potential way to address the high cost of biologic medicines. Unlike generic versions of conventional drugs, biosimilars are highly similar to, but not identical to, their originator products and have no clinically meaningful differences from them. A federal policy enacted in 2009 was designed to establish an abbreviated regulatory pathway for biosimilars in the U.S. market to increase competition, lower prices and improve access to biologic treatments. By the end of 2024, 13 biosimilars were available for three major cancer biologics: bevacizumab, rituximab and trastuzumab. These drugs are used to treat cancers including breast cancer, lymphoma, colorectal cancer, lung cancer and ovarian cancer.
Previous studies have found that biosimilar competition in other therapeutic areas can lower prices and increase use of these lower-cost alternatives. However, less was known about how biosimilar entry across these three major cancer drugs affected the prices and market share of the original branded biologics and, importantly, whether those changes translated into lower costs for insurers and patients. The new study sought to address this gap by examining the economic impact of biosimilar use in real-world cancer care.
What the study did
Researchers conducted a retrospective cohort study using health insurance claims data to examine the use and costs of three cancer biologics after biosimilars became available for each. They analyzed data from 14,655 patient-drug pairs involving people with cancer who initiated bevacizumab, rituximab or trastuzumab between 2020 and 2023. The study included patients with commercial insurance and Medicare-related coverage and tracked their treatment and costs for 12 months after they began treatment with a biologic.
The researchers grouped patients based on whether they exclusively used a biosimilar, exclusively used the originator, switched from the originator to a biosimilar, or switched from a biosimilar to the originator. They compared monthly costs paid by insurers and patients' out-of-pocket payment, calculated as the sum of deductibles, copayments and coinsurance. They also examined changes in the average sales price and market share of the originators and their biosimilars from before biosimilar entry through 2024 to assess how the introduction of biosimilars affected the market dynamics.
What they found
Among the patient-drug pairs, 59.4% of patients exclusively used a biosimilar during the first 12 months of treatment, while 32.5% exclusively used the originator. About 6.9% of patients switched from the originator to a biosimilar, and 1.2% switched from a biosimilar to the originator. This suggests that biosimilars were adopted primarily by patients starting treatment rather than through switching patients who were already receiving the originator.
Patients who exclusively used biosimilars were associated with substantially lower monthly costs for insurers. After adjusting for differences among patients and treatment patterns, average monthly payer costs were $8,959 for patients who exclusively used biosimilars, compared with $12,779 for those who exclusively used the originator, a difference of $3,820 per month. Patients who exclusively used biosimilars also had lower average monthly out-of-pocket costs, $118.90 compared with $158.40 for those who exclusively used the originator, a savings of $39.50 per month.
The researchers also found that biosimilar entry was associated with lower prices and declining market share for the originators. The average sales price of the three originators declined by 3.8% per year after biosimilars entered the market, while their market share decreased by about 30% annually among patients with commercial insurance and 31.5% in Medicare Part B. The average sales price of the 12 biosimilars included in the study declined by 12.4% per year.
What this means for patients
The findings suggest that biosimilars could help reduce some of the financial burden associated with cancer treatment for patients while creating savings for the healthcare system.
"Although the savings were substantially greater for insurers than for patients, even modest reductions in out-of-pocket costs may be meaningful for people facing the financial challenges of cancer care – savings that can be used toward other treatment-related expenses or cover living expenses," said Tina Shih, PhD , director of the Cancer Health Economics Research Program at the UCLA Health Jonsson Comprehensive Cancer Center, professor of Health Economics in the Department of Radiation Oncology, and senior author of the study.
The study also points to treatment initiation as an important opportunity to expand biosimilar use. Because most patients in the study who received biosimilars started treatment with them, rather than switching from an original biologic, decisions about which drug to use when treatment begins may play an important role in increasing access to lower-cost and equally efficacious alternatives.
"The FDA has continued to take regulatory actions aimed at further unlocking biosimilar competition recently," said Xiaoyu Liu, PhD, first author of this study. Our study findings offered further evidence to support patients, providers and insurers in their consideration of biosimilars."
About the researchers
The study's first author is Xiaoyu Liu, PhD, a former PhD student in the Department of Health Policy & Management at the UCLA Fielding School of Public Health. The other authors are Xiaoyi Xu, MS and Z. JohnLu, PhD from UCLA.
