Comparison of Biosimilars vs Biologic Agents

Clinical pharmacists provide an overview of the similarities and differences of biosimilars vs biologics including a comparison of dosing and storage conditions.

Anthony Mato, MD, MSCE: The regulation marketing and clinical testing of biosimilar agents has been difficult. With the growing number of biosimilars available in oncology, it is important to understand the challenges in policy and coverage decisions. Clinical pharmacists are in a unique position to provide appropriate patient and provider education. There’s also an increased impact by pharmacists in managing the formularies with multiple biosimilars available. Our panel of experts will provide commentary and updates on biosimilars in the marketplace.

I’m Dr Anthony Mato, director of the CLL [chronic lymphocytic leukemia] program at Memorial Sloan Kettering Cancer Center in New York, New York. Today I’m joined by Dr Marc Earl, director of pharmacy at Cleveland Clinic in Cleveland, Ohio; Dr Tim Peterson, myeloma clinical pharmacy specialist at Memorial Sloan Kettering Cancer Center; and finally, Dr Bhavesh Shah, senior director of specialty pharmacy at Boston Medical Center in Boston, Massachusetts. Thank you for joining us. Let’s begin.

We have an audience here who may have differing degrees of knowledge of biosimilars. I think it’s very important to start by defining biosimilars and discussing their similarities and the differences between biosimilars and the biologics. Tim, would you be willing to tackle that first question?

Tim Peterson, PharmD, BCOP: Absolutely. To adequately define what biosimilars really are, I think we really need to take a step back and think about biologics, about a therapeutic class. This is because we know that biologics represent the largest-growing therapeutic class in the United States. Biologic agents are very different from the small-molecule drugs we’re familiar with. For small-molecule drugs, the brand originator versus the generic, it’s very easy to re-create these identical copies with a chemical synthesis. We have these raw materials that we know the chemical formula for, so we can identically make these copies.

For biologics, because they’re developed from recombinant DNA using a vector inserted into a host cell and these types of things, they can be very large molecules with very high molecular weights. They’re very complicated, utilizing proteins, sugars, and nucleic acids. We’re talking about differences in amino acid sequences and protein aggregation and folding. There can be a lot of variability, even within 1 manufacturer producing biologics from lot to lot with different processing changes and that type of thing.

When we look at biosimilars, the FDA has defined a biosimilar as something that does not have any clinically significant difference in the safety, the purity, or the potency when compared with the originator product—the reference product. This is looking primarily at analytical studies that we’ll touch on, but they look at the structure and the function, and they look at how these may or may not affect the bioactivity of these agents.

Anthony Mato, MD, MSCE: What about dosing, route, and storage conditions? Are there any differences we need to point out there?

Tim Peterson, PharmD, BCOP: When we’re comparing biosimilars with the reference products, they are going to maintain the same dosing route of administration and generally concentration. But with regard to storage, I’ll pass it over to Bhavesh. Maybe you can touch on some of the storage differences.

Bhavesh Shah, RPh, BCOP: We’ve noticed, when we adopted Inflectra [infliximab], that there were data that were not available for storage. We noticed that Remicade [infliximab] actually has 6 months of room temperature storage, which Inflectra didn’t have, and I think that has to do with how long the drug is available in the market and the manufacturer who has had time to do studies in those settings. In newly approved biosimilars, we may not see those changes, but I think eventually we’ll see the similarities in the storage between the molecules. There are differences with various other biosimilars and reference products in terms of storage requirements, so we should definitely be aware of that as we are adopting these new agents.