Bevacizumab Biosimilar Comparable to Reference Across Disease States

Across a variety of disease states, medication utilization and safety outcomes were similar between reference bevacizumab (Avastin) and bevacizumab-awwb (Mvasi), according to a paper published in Hospital Pharmacy.

There are 3 bevacizumab biosimilars approved in the United States across a variety of cancers: colorectal cancer, nonsquamous non–small cell lung cancer, glioblastoma, kidney cancer, cervical cancer, and renal cell carcinoma. The first approval was Mvasi in September 2017 with a launch of July 2019. In June 2019, Zirabev was approved and launched December 2019. Most recently, Alymsys was approved April 2022 but has not yet launched.

Biosimilars are able to come to market at a reduced price to the reference biologic because they go through an abbreviated approval pathway that does not require costly clinical efficacy trials for all product indications. “An increased importance is therefore placed on postmarketing surveillance of biosimilars to supplement existing evidence and enhance patient and provider confidence in their safety and efficacy,” the authors explained.

They evaluated the utilization, safety, and financial outcomes of bevacizumab-awwb compared with the reference product in a single-center, retrospective, indication-matched cohort study. The adult patients in the study received either the reference or the biosimilar between October 1, 2019, and October 1, 2020.

A total of 68 patients were included, with 34 receiving the reference and 34 receiving the biosimilar. Both groups had the same proportion of diseases, with 19 patients with colorectal cancer, 10 patients with gynecologic cancer, 3 patients with glioblastoma, 1 patient with hepatocellular carcinoma, and 1 patient with non–small cell lung cancer.

Patients on the reference product had a higher proportion of public payer coverage compared with the biosimilar group (64.7% vs 38.2%; P = .029).

At the end of the study, 52.9% of patients in the biosimilar group were still on active treatment compared with just 35.3% of patients in the reference group. The 2 groups had equal rates of worsened hypertension from baseline. A higher proportion of patients in the reference group experienced grade 1 or 2 worsened proteinuria, but the difference was not significant.

Overall, the medication utilization and safety outcomes were similar for the 2 groups, which aligns with past evidence of the biosimilar compared with the reference product, the authors wrote.

There was a 15.8% discount on median drug cost per dose for the biosimilar compared with the reference product and a 12.2% discount per milligram. For the biosimilar, reimbursement as a percent of charge was 26.6% greater, which the authors attributed to the higher proportion of private payers. The biosimilar group also had a greater median gross profit margin (52.2%), “emphasizing the significant opportunities for cost-savings associated with biosimilars.”

The limitations of the study were the retrospective study design, the limited sample size, and the short time frame, which did not capture the total duration of therapy. Another limitation was that the study only reviewed 1 approved biosimilar because no patients at the institution were receiving the other launched biosimilar, Zirabev.

While the heterogenicity of the patient population limits generalizability and the conclusions that can be drawn, it allows for potential differences across a wide variety of disease states to be explored, the authors noted.

“Postmarketing surveillance of biosimilars to supplement existing evidence may serve to enhance patient and provider acceptance,” they concluded.

Reference

Philippon Booth J, Pilz J. Retrospective indication-matched cohort study of reference product and biosimilar: bevacizumab versus bevacizumab-awwb. Hosp Pharm. 2022;57(4):455-461. doi:10.1177/00185787211046865