Biosimilars provide modest cost savings for cancer patients, study finds

Cancer biosimilars are associated with lower costs for both insurers and patients, according to a new study by researchers at the UCLA Health Jonsson Comprehensive Cancer Center. 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 costs compared with patients who exclusively used the branded biologic drugs, according to a study published today in JAMA Oncology.

“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,” senior author Tina Shih, Ph.D., director of the Cancer Health Economics Research Program at the UCLA Health Jonsson Comprehensive Cancer Center, said in a news release. Shih is also a professor of Health Economics in the Department of Radiation Oncology.

In this analysis, researchers conducted a retrospective cohort study using claims data from the Merative MarketScan commercial database and the Medicare database. They examined the use and costs of three cancer biologics after biosimilars became available. They analyzed data from 14,655 people with cancer who began treatment with bevacizumab (Avastin and four biosimilars), rituximab (Rituxan and three biosimilars) or trastuzumab (Herceptin and five biosimilars) between 2020 and 2023.

Researchers grouped patients based on whether they exclusively used a biosimilar, exclusively used the branded product, switched from the brand to a biosimilar, or switched from a biosimilar to the brand. In this analysis, 59.4% of patients exclusively used a biosimilar during the first 12 months of treatment, and 32.5% of patients exclusively used the branded product.

They then compared monthly costs paid by insurers and patients’ out-of-pocket payments, calculated as the sum of deductibles, copayments and coinsurance. Researchers also assessed changes in the average sales price of the brand and their biosimilars from before biosimilar entry through 2024.

What researchers found was that biosimilars lowered both payer and patient costs. Patients who exclusively used biosimilars were associated with substantially lower monthly costs for insurers. Average monthly payer costs were $8,959 for patients who exclusively used biosimilars, compared with $12,779 for those who exclusively used the branded drug, 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 brand, 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.

Related: Biosimilars are driving down costs and increasing access to biologics

These findings are in line with previous research done by the Specialty Drug Evidence and Coverage (SPEC) Database at Tufts University. James D. Chambers, Ph.D., a professor at Tufts University School of Medicine and an investigator at Tufts Medical Center, and his team have shown that biosimilar competition puts significant downward pressure on the price of a molecule once a biosimilar enters the market, with declines reaching up to 70% over time in some cases.

In an interview earlier this month, Chambers said more work needs to be done to make sure that patients are seeing a reduction in their out-of-pocket payments alongside the biosimilars.

UCLA researchers noted one limitation of their analysis is that average sale price reduction may be that it is understated because they used a static price point. Additionally, they assessed market share data from claims data rather than drug volume or revenue measures.

Still, they say their analysis provides “further arguments for a rapid and extensive insurance coverage promoting the use of biosimilars in cancer treatment.”