Ophthalmologists See Promise and Peril, but Lack Familiarity, With Biosimilars

In the oncology space, there are 19 biosimilars approved in the United States, with the first approval as early as August 2012, which has given oncologists a lot of time to become comfortable with switching to biosimilars. However, other disease states have not seen the same uptake.

In a new editorial published in Ophthalmology Retina, authors highlighted the promise of ophthalmology biosimilars, as well as some of the perils with them.

The 2022 Biosimilars Report from Cardinal Health highlighted that in some therapeutic categories, such as ophthalmology, biosimilars are very new. For instance, the first experience ophthalmologists had with biosimilars was less than agreeable.

In ophthalmology, prescribing bevacizumab off label to treat retinal diseases in the first line is not uncommon, explained Paul Hahn, MD, vitreoretinal surgeon at NJRetina, who presented results of the Preferences and Trends survey at the recent American Society of Retina Specialists 40th Annual Scientific Meeting.

Bevacizumab, which is approved for 8 cancer indications, including glioblastoma, renal cell carcinoma, and non–small cell lung cancer, is used off-label to treat wet age-related macular degeneration. Treatment with bevacizumab involves an injection to the eye.

There are 3 approved bevacizumab biosimilars, with the first 2 launching in the United States in July and December 2019 (Mvasi and Zirabev, respectively). In 2021, the American Academy of Ophthalmology released a statement that insurance companies were pushing ophthalmologists to use newly available bevacizumab biosimilars as alternatives to the reference product.

The organization opposed this because the bevacizumab biosimilars had never been tested in the eye, and the “drugs’ manufacturers have advised against injecting the alternative drugs into the eye because there is no scientific proof to support it.” Furthermore, one of the biosimilars is prepared with an agent that “has demonstrated toxicity to corneal and conjunctival epithelial cells.”

As a result, US ophthalmologists have had no experience with any FDA-approved biosimilars until mid-2022. In September 2021, the FDA approved the first biosimilar in ophthalmology, a ranibizumab biosimilar (Byooviz), and it launched in the United States in June 2022. According to the authors, the introduction of an approved ranibizumab biosimilar has “substantial implications for retinal drug therapy.”

Cardinal’s report found that ophthalmologists were not familiar with biosimilars, with only 40% saying they were very familiar compared with 63% of diabetes prescribers, 55% of oncology prescribers, and 53% of rheumatology prescribers. Ophthalmology prescribers were also more likely to respond “I am not likely to prescribe a biosimilar for any patient at this time” (25%) compared with 2% in diabetes, 5% in oncology, and 7% in rheumatology.

In addition, 38% of ophthalmologists said their primary concern with prescribing biosimilars when they become available was that they were uncomfortable from a clinical standpoint, and 82% said that in order to achieve a greater understanding of biosimilars, they would need educational information about safety, efficacy, and performance.

One of the biggest promises of biosimilars has been the cost-saving aspect. However, the authors of the editorial noted that the 2 most commonly used FDA-approved ophthalmic biologics, ranibizumab and aflibercept, have not had any price increases since their approval.

“In fact, the Medicare-allowable payments for both drugs have decreased (7% for aflibercept and 26% for ranibizumab),” they wrote. “Whether the advent of retinal biosimilars will further lower costs will depend on the biosimilar pricing and market share.”

In addition to a new ranibizumab biosimilar now available in the United States, there is a bevacizumab biosimilar in the works. Bevacizumab-vikg has completed clinical trials; however, because bevacizumab is not approved for any ocular indications, it will actually be submitted for review as a novel drug through the normal biologic licensing pathway, the authors explained. The approval of this bevacizumab biosimilar may affect access to compounded bevacizumab, which “is used in approximately 40% of intravitreal injections.”

In addition, there are aflibercept biosimilars under development. The patent on the reference product, Eylea, does not expire until June 16, 2023.

“The advent of ocular biosimilars holds great promise for improved patient access and potential cost savings,” the authors concluded. “However, within this promise lie the perils of increasing administrative and regulatory burdens and costs.”

Reference

Williams GA, Repka MX, Glasser DB. The promise and periods of biosimilars in ophthalmology. Ophthalmol Retina. 2022;6(7):537-539. doi:10.1016/j.oret.2022.03.018