Carl D. Regillo, MD, and Jennifer I. Lim, MD, caution against the ophthalmic use of biosimilar products approved for systemic use. They also review how indications for biosimilars are granted upon approval.
Carl D. Regillo, MD: In our field, we have on-label biologics: ranibizumab, aflibercept, brolucizumab, and faricimab. But for many years, we’ve been using off-label bevacizumab injected in the eye and have had, more or less, a good experience with it and its efficacy and safety. There are now biosimilars to bevacizumab. The [American Academy of Ophthalmology] got involved because payers started to encourage, or mandate, I’m not sure what they actually did, but there was something that was put out there that we should be using these in the eye.
Jennifer I. Lim, MD: That’s crucial to understand because when we look at these biosimilars for bevacizumab, we must realize that these are different in terms of the excipients. It hasn’t been tested in the eye. The Academy of Ophthalmology policy statement says we must be very careful, we can’t just take a drug that’s never been used in the eye just because it is biosimilar to bevacizumab. Specifically when we look at these, we must test that biosimilar in the eyeball; we can’t take these off the shelf and say, “Oh, well, it’s bevacizumab,” and inject it into the eyeball. We must have studies, this is what the academy says. With bevacizumab, we have the CAT trial that showed that it was safe. We also have the DRCR.net [Diabetic Retinopathy Clinical Research Network] studies that compared a bevacizumab formulation, as given, to the other drugs that are out there. We don’t have this for the biosimilars for bevacizumab. As of today, I want to make sure everybody realizes we can’t just formulate these. It’s very important that the insurance companies do not make us use this because it could be disastrous in the eye.
Carl D. Regillo, MD: The FDA standards for safety and purity of a product to be used intravenously or systemically is different than the eye. The eye is, in essence, a more sensitive organ system, so what may be tolerated intravenously may not be in the eye. The academy has made an official statement that we should not be using a biosimilar of bevacizumab–which was biosimilar for systemic administration–to be used in the eye.
Jennifer I. Lim, MD: Exactly, because of the excipients, the other things that are the nonbiologic portions that can have disastrous effects in the eye.
Carl D. Regillo, MD: An important distinction. One other interesting or unique aspect to a biosimilar is that the equivalency studies that we’ve been talking about were testing the product against the reference product in 1 specific disease state. The 2 studies we talked about were for neovascular AMD [age-related macular degeneration], and yet the approval could potentially be for more or other conditions, is that right?
Jennifer I. Lim, MD: That’s right. This is the difference with these biosimilars. Once you prove that a drug is biosimilar, the biosimilar is equivalent to the reference drug, you then gain the indications that the reference drug already had. Specifically, for SB11, which was shown to be equivalent to ranibizumab, this was a dose of ranibizumab 0.5 mg. All the indications that ranibizumab 0.5 mg has, you can use SB11 for; so that is, neovascular AMD, retinal vein occlusion, and myopic CNV [choroidal neovascularization]. You’re probably wondering, can I use it for diabetes? The answer is no because that was 0.3 mg ranibizumab for the approval, so that is not yet out there.
Carl D. Regillo, MD: At least in the United States.
Jennifer I. Lim, MD: At least in the United States, yes, right, because they do use 0.5 mg in Europe. If you live in Europe, you can use it.
Transcript edited for clarity