US Insurers Often Limit Biosimilar Coverage

By Lisa Rapaport

May 29, 2020

(Reuters Health) - U.S. commercial health plans only covered biosimilars as "preferred" products in 14% of coverage decisions last year, according to an analysis of publicly available data on coverage decisions.

Researchers examined records from the Tufts Medical Center Specialty Drug Evidence and Coverage (SPEC) database, which has information on coverage decisions made by 17 of the largest U.S. health plans that publicly share this data.

Based on 535 coverage decisions in 2019 that involved 9 biosimilars and 40 drug-indication pairings of biosimilars and reference products for the same indication, biosimilars received "non-preferred" status in 33% of cases and "on par" status in 53% of decisions.

"These findings have important implications for patients, as they mean that a patient's insurer can affect their access to biosimilars," said lead study author James Chambers of the Center for the Evaluation of Value and Risk in Health at Tufts Medical Center in Boston.

"Our findings may also have important implications for patients transitioning between insurers, as differences in insurance plans' coverage decisions may result in care disruptions," Chambers said by email.

The health plans in the study issued a median of 32 biosimilar coverage decisions, with a range of 18 to 40 decisions.

Researchers looked at nine biosimilar drugs: bevacizumab-awwb, epoetin alpha-epbx, filgrastim-aafi, filgrastim-sndz, infliximab-abda, infliximab-dyyb, pegfilgrastim-cbqv, pegfilgrastim-jmdb, and trastuzumab-anns.

Across all of the health plans in the study, the media number of coverage decisions for an individual biosimilar was 56, and ranged from 12 to 134.

Seven health plans covered a biosimilar as preferred in at least one decision, and only two of these plans preferred biosimilars in at least half of their coverage decisions.

Decisions also varied by drug. While 51% of plans covered filgrastim-sndz as preferred, for, example, 65% of plans covered infliximab-abda as non-preferred.

Researchers lacked data to explain why there was so much variation in coverage decisions, and they also lacked information on any negotiated rebates that might have contributed to any decisions based on the relative costs of different drugs.

Drug characteristics, such as the time since FDA approval or whether the drug treats cancer, may explain some of the variation, the authors note.

"Insurance plans and their Pharmacy Benefit Managers (PBMs) seek deals with drug manufacturers not only based on discounts from the list price, but by negotiating rebates," said Donald Miller, a professor of pharmacy practice at North Dakota State University in Fargo who wasn't involved in the study.

"Often manufacturers offer large rebates to PBMs that keep the actual price of a reference drug to the PBM below that of the biosimilar," Miller said by email.

Limitations of the study include the lack of information on appeals for coverage denials and on the benefit design of health plans including any co-insurance or co-payments.

"The way many drug insurance plans are structured, the biosimilar may not be cheaper for patients," said Dr. Daniel Solomon of Brigham and Women's Hospital and Harvard Medical School in Boston.

"The rationale is difficult to understand," Dr. Solomon, who wasn't involved in the study, said by email. "Patients should always shop around and get details before deciding on an insurance option."

Several authors of the research letter reported receiving grants from or consulting for biotech or pharmaceutical companies and other organizations.

SOURCE: JAMA, online May 19, 2020.