How similar is a biosimilar?

Biosimilars, which have similar structure and function to their reference formulations, have no clinically meaningful differences from the reference products.

The availability of biosimilar products has brought ophthalmology into a new era—one that also introduces new considerations for ophthalmologists, according to George A. Williams, MD.

Williams is the American Academy of Ophthalmology, Senior Secretary for Advocacy and Chair, Department of Ophthalmology, and Director of the Beaumont Eye Institute at Beaumont Health, Royal Oak, MI.

Biosimilars, which have similar structure and function to their reference formulations, have no clinically meaningful differences from the reference products.

Two such products are currently available to ophthalmologists: the first is Byooviz (ranibizumab-nuna, Biogen and Samsung Bioepis), approved for all FDA indications for ranibizumab 0.5 mg (Lucentis, Genentech) for age-related macular degeneration and other ocular diseases, and the second is Cimerli (ranibizumab-eqrn 0.5 and 0.3 mg, Coherus BioSciences), which received FDA approval as a biosimilar interchangeable with ranibizumab injections for 5 indications.

Approval is now being sought for another biosimilar formulation, Lytenava (bevacizumab-vikg, Outlook Therapeutics) for ocular diseases. Following the first filing, the FDA requested additional data. A concern raised about this biosimilar was whether it will affect access to compounded Avastin (bevacizumab, Genentech) as a result of FDA regulations and limitations on compounding of FDA-approved products, Williams explained.

This consideration raised the following question: How similar is a biosimilar? “If biosimilars are considered new molecular entities, perhaps there will be no problems,” he commented.

Other questions surrounding biosimilars=

Williams believes that considerations surrounding the use of biosimilar will revolve mostly around step therapy and where biosimilars will be integrated into step-therapy protocols: will failure of the sequence of compounded bevacizumab, bevacizumab-vikg, and 1 or both ranibizumab biosimilars before access to any branded drug that was approved as noninferior to ranibizumab have to occur first? These considerations also will apply to future biosimilars developed, for example, for aflibercept (Eylea, Regeneron Pharmaceuticals).

He also described the concepts of “brown bagging” and “white bagging.”

In both instances, the pharmacy buys drug from the company/intermediary supplier and bills the payer. In the former situation, the patient picks up the drug and carries it to the physician for administration in contrast to the latter in which the pharmacy ships the drug to the physician. In both cases, the physician bills only for administering the drug.

Possible considerations with this system are that the drug is available to only a specific patient, the physician cannot change the drug, drugs must be ordered before an examination, shipping delays can occur with white bagging, loss of drug chain integrity is likely with brown bagging, and physicians must maintain the drug delivery infrastructure without a drug margin, Williams commented.

“The implications for biosimilars in clinical practice are interesting and remain to be determined,” he stated and advised ophthalmologists to gain insights from oncologists about brown bagging and white bagging.