Drs Roy M. Fleischmann and Joel M. Gelfand define interchangeability status and discuss its impact on the field of dermatology and rheumatology.
Roy M. Fleischmann, MD: Joel, what does this very complex discussion that I just went through mean to the practicing physician?
Joel M. Gelfand, MD, MSCE, FAAD: What our colleagues need to know is that if a biosimilar is granted interchangeability status by the FDA, that basically means that the pharmacist can change your originator prescription to an interchangeable biologic that’s targeting the same molecule—TNF [tumor necrosis factor] or what have you—in a very similar manner, as we just went through. But you may not be aware of that switch that may occur in your patient. For 6 months, they may be getting an originator product. The next 6 months, they may be getting the interchangeable biosimilar. The next 6 months, they may be getting another interchangeable biosimilar.
They’re all targeting the originator molecule, which is a key thing for clinicians to be aware of, but questions will come back from our patients asking, “Is this OK? I got this new thing. It doesn’t have the same name as adalimumab.” In generics, they’re all called doxycycline or hydroxychloroquine or whatever small molecule it is. Biosimilars have different names. They aren’t going to all be called adalimumab. It’ll be a biosimilar version of adalimumab that has a different name, so the patient will be very aware that things have been changed on them.
Roy M. Fleischmann, MD: Yes. The other point I’d make is that it will not only have a different name, it may have a different delivery system. Instead of a pen that’s 2 inches long and a ½-inch wide, it may be 3 inches long and a quarter-inch wide. The needle may be ⅝ of an inch or ½ an inch.
Joel M. Gelfand, MD, MSCE, FAAD: It may be an autoinjector or not an autoinjector. It may be buffered with citrate or not buffered with citrate. The patient will likely come back to us with questions, such as, “How do I use this injector?” They might say, “All of sudden, it’s painful when I’m injecting this thing that you told me is similar to my previous biologic.”
Roy M. Fleischmann, MD: To summarize, to be approved as a biosimilar, it’s the regulatory process that Joel and I went through before. You have to do all the analytical studies to show that it’s generally similar, usually within a range of about 15% in a clinical study with the reference product, and that’s all you need. But to be interchangeable, it’s a much more complex process to get FDA approval. Not all biosimilars are interchangeable, and they can’t be interchangeable until they get the FDA approval.
Transcript Edited for Clarity