How to Switch Patients to Biosimilars

Roy M Fleischman, MD: The other point you raised was that if a patient does not respond to the branded product adalimumab, would you expect them to respond to the biosimilar? I agree with you. Why should they? They don’t. The probability that this is not the case is probably 98%. Why take that 2% chance? Why not just switch the drug or mechanism?

Joel M Gelfand, MD, MSCE, FAAD: Yes, but if a person did well with the original product and then over time lost the reaction, do you think they have a chance to win back? [response] if they go to a biosimilar?

Roy M Fleischman, MD: You can, but it’s highly unlikely.

Joel M Gelfand, MD, MSCE, FAAD: That’s what most of our colleagues think. Clinicians need to think about these things. At what stages do I say it’s okay to try a biosimilar and I won’t mind? Are there any particular clinical circumstances where I could say, “I don’t want my patient to have this biosimilar.”

In my own practice, one of the major challenges in treating psoriasis is that some patients tend to cycle through therapies. They do well for a while, then they lose the reaction. Then they do well, then they lose the reaction again. I worry about these people because eventually they will run out of options. For these people, I would say if someone does well with a product, “There is enough uncertainty here, we should stick with the original product in this unique individual case as long as it is doing well and not risk an unknown circumstance. ”These unique individual patient circumstances that constitute the practice of clinical medicine are difficult to test in the typical studies.

Roy M Fleischman, MD: I’ll do it differently. If I have a patient with psoriatic arthritis and want to start TNF [tumor necrosis factor] Inhibitor and I have the option of using adalimumab as a reference or the biosimilar adalimumab I don’t care.

Joel M Gelfand, MD, MSCE, FAAD: I totally agree. The question is the person who takes the biologic and is fine.

Roy M Fleischman, MD: The studies and registry data from Europe showed me that if a patient is doing well with the reference product and you then switch them to the biosimilar, you explain to them what the biosimilar is and that they shouldn’t be too scared even though they are have been doing great for 3 years, the chances that they will react and do great are still very good. The only caveat that would be part of the deal is that I will switch the patient to the biosimilar, but if the patient doesn’t respond I want to go back to the bio-original.

Joel M Gelfand, MD, MSCE, FAAD: Yes. We’ll find out as these become more widely used in the US market. Is this a problem? The clinical trials themselves often do not fully reflect the patient population we need to treat. You often won’t have people who weigh 400 pounds who have already gone through 4 biologics and are finally well controlled with the current MOA [mechanism of action]. These individuals are not well represented in these FDA pivotal studies and individual clinical decision making must take place in these circumstances.

Roy M Fleischman, MD: Yes. To follow your line of thinking, which is also unknown and therefore still problematic is when we will get 4 biosimilars of adalimumab that will receive an interchangeability designation. It is up to the pharmacist whether your state allows this. Not Texas, by the way. I think Pennsylvania does. Let’s assume the patient is fine with the reference product. You think the patient is fine. The pharmacist converts them into an interchangeable biosimilar. You’re not sure if this is the right thing to do, but you can’t comment and the patient remains fine.

Four weeks later, another adalimumab biosimilar is interchangeable and cheaper. The pharmacist who works for a PBM [pharmacy benefit manager], who is just out for profit, says, “I’ll switch you to the other biosimilar.” Now you’ve gone from the reference product to biosimilar 1 to biosimilar 2, and the real risk is immunogenicity, or there are small differences between the molecules , about which you spoke so eloquently before. Maybe they’re just a little different. Will the patient respond? I do not know. Then they turn around and say, “Now I want to go back to the reference,” because the company has lowered its price tremendously. Over the course of a year, the patient ends up on the reference product three times, biosimilar 1 three times, biosimilar 2 three times, and biosimilar 4 three times. We don’t know what that will do.

Joel M Gelfand, MD, MSCE, FAAD: That is exactly right. These will be the clinical puzzles that our colleagues and we will face in the future when these biosimilars are finally accepted in the United States.

Transcript edited for clarity