Role of Biosimilars in Breast Cancer

Jacob Kettle, PharmD, BCOP, and Allison Butts, PharmD, BCOP, discuss the role of biosimilars in the management of breast cancer.

Jacob Kettle, PharmD, BCOP: In addition to new molecules, the breast cancer therapy world has absolutely been transformed the last couple of years, particularly last year in general, over the availability of biosimilars. For trastuzumab alone, we have several biosimilars, FDA approved and available, and there are more to come. I’m curious: Purely from a clinical perspective, what’s been your approach to evaluating biosimilars?

Allison Butts, PharmD, BCOP: Our center [at the University of Kentucky Markey Cancer Center] has been open to biosimilars. We could certainly expound upon some of the payer issues that go along with biosimilars and what we end up needing to use based on what the payers will allow for a particular patient. From a clinical standpoint, I don’t have any issues or concerns with using biosimilar trastuzumab products.

Jacob Kettle, PharmD, BCOP: Is there anything in the approval of a drug that you look for unique, or is FDA approval the ultimate seal of approval?

Allison Butts, PharmD, BCOP: From those that I’ve looked into more deeply, the studies that are done and the standards that are set by the FDA are thorough enough to make me comfortable. Infusion reactions are interesting when we’re talking about monoclonals because that’s certainly a concern with any of them across the board. That’s something that—if we’re looking at a different way of producing these agents, does that rate of infusion reaction change or not?

Jacob Kettle, PharmD, BCOP: Interesting. I’m curious if you or anyone had issues. A lot of these drugs rely on some extrapolation. When you do that in the supportive care space, the metastatic setting, that’s a bit of a different discussion from what we’re now we’re talking about with trastuzumab in early breast cancer. Were there any issues for you or the folks you work with getting over that extrapolation in a curative setting?

Allison Butts, PharmD, BCOP: There were not. They can show that it’s effectively targeting HER2 [human epidermal growth factor receptor 2] in this case; it’s effectively clearing out and leaving the body as it’s supposed to. Surprisingly, there was not a lot of pushback on our end for those agents.

Jacob Kettle, PharmD, BCOP: For better or for worse, I deal more on the administrative side. What we find is that our biggest issue with biosimilars is figuring out how to operationalize and optimize them. We have a lot of different payer mandates in the mix that preclude us from being able to drive the ship to what may be the best for our own institution. One payer may prefer product A for clinical, operational, and financial reasons, what have you. Another payer may like product B, and another may like product C. Half of patients are still on the originator product because they’ve been on it for 5 years, and we don’t want to disrupt them.

That creates a nightmare scenario from ordering, authorizations, and drug dispensing. To me, that is the bigger hurdle that we’ve encountered with biosimilars and how they play a role in cancer therapy. The clinical hurdle is about how you operationalize and utilize these drugs. It’s definitely a real and useful cost-saving opportunity. The challenge for us has always been how do we leverage that into improving the patient experience and advancing cancer care at large? The small picture is operationalizing them, and the bigger picture is about how we take the advantages they may bring to our practice but leverage that to advance our mission.

Allison Butts, PharmD, BCOP: That’s a great point. You have to draw the line somewhere. You can’t have 10 trastuzumab products sitting in your refrigerator. You can’t have 10 line items for each trastuzumab-containing order set of which biosimilars preferred for that patient. Even consenting is important; we spend a fair amount of time talking about updating our consent form to reflect the possibility that patients will get biosimilars.

Jacob Kettle, PharmD, BCOP: Yeah.

Allison Butts, PharmD, BCOP: Do you consent them based on the parent-product of trastuzumab? Do you need to consent them for the possibility of biosimilars? How does that all tie into initiating these drugs? It’s tough.

Jacob Kettle, PharmD, BCOP: Yes, it’s tough.