Ryan Haumschild, PharmD, MS, MBA: I appreciated the discussion about therapy because it’s important that we think about real evidence. If we switch from an aromatase inhibitor to fulvestrant, what is the clinical benefit? Speaking of clinical utility, perhaps Dr. Dent go ahead with it. Which clinical endpoints do you consider therapy goals? When I talk to patients, they are often more interested in overall survival. Some [are more interested in] progression-free survival. What are these endpoints that you notice that you use to monitor response to therapy? At what point do you consider switching a patient if you feel they are not meeting the desired endpoint?
Susan Faye Dent, MD, FRCPC, FICQS: That’s a good question. Historically, if you look at drug approval, overall survival has been the gold standard. Everyone wants to live longer with their illness. You want to survive. As a clinician, I think patients still benefit from progression-free survival, which is what many of the studies are examining. All of the CDK4/6 inhibitors available to us were originally approved on the basis of progression-free survival. Because if you can keep someone from making progress longer, it means you’re keeping them healthy longer. Importantly, you also keep her away from chemotherapy for longer.
Based on this, some studies have used time to start chemotherapy as an endpoint, which is interesting. Quality of life is an important endpoint. All of these things are about keeping someone on the therapy that is best tolerated, works, and has the least impact on quality of life [are important]. Overall survival is important, but other endpoints such as progression-free survival, time to chemotherapy, and quality of life are just as important.
Ryan Haumschild, PharmD, MS, MBA: As we talk about some of these clinical endpoints, we realize that we cannot achieve them alone. It [requires] the patient to be engaged. Good adherence to therapy, management and understanding of treatment goals are important. Pharmacists have an important role to play in this, so I’ll turn this question over to Dr. Moore, who works directly with breast cancer patients at the clinic every day. What do you think is the important role that pharmacists play in treating these patients and sometimes in mutation screening, education, monitoring and follow-up of the diagnosis? Give us a little context on the important role you play as a pharmacist in the clinic.
Heather N. Moore, PharmD, BCOP, CPP: First, we are the drug experts. That’s essentially what we do. like dr Dent alluded to, the entirety of FDA-prescribed and approved oncology drugs is changing so rapidly that there are many complexities and toxicities that open the door for pharmacists. You mentioned a few of them. One is education. [It’s important to] Make sure the patient feels empowered by the therapy they receive and how they use it at home. There are many things we overlook, including whether it is taken with food. This is important from the patient’s point of view.
I think of toxicity management when we think of all of our therapies related to breast cancer. I can’t stress this enough. We’ll get into that a little more, but I’m thinking specifically about alpelisib-induced toxicities, hyperglycemia, rash, neutropenia, diarrhea, and nausea that we’re seeing with some of our CDK4/6 inhibitors. As we move away from chemotherapy, many of our targeted therapies come with so many toxicities that we need to know how to manage them. What good is a drug if you can’t keep up with it?
The other important consideration for pharmacists is drug interactions. We think about drug interactions, and most people think about CYPs, not just from a pharmacokinetic standpoint, but pharmacodynamic interactions as well. A lot of what we see are patients with comorbidities. Many of our patients are post-transplant patients, patients with possible chronic kidney disease, or patients with multiple comorbidities where we essentially need to find ways to make the drug work for the patient. We basically find the best therapy for patients and help identify which different drugs within a class might be best. Probably the best example of this would be CDK4/6 inhibitors. We have 3 different ones [drugs] within this class and [we need to] choose what is best for that patient.
Susan Faye Dent, MD, FRCPC, FICQS: Can I build on this? I want to be very clear about having a pharmacist on board. I am very fortunate that we work side by side in the clinic and how valuable that is. More importantly, you brought me another aspect to the previous question that I didn’t quite get, namely: What would make you change your therapy? Why would you change the therapy in a patient who gets something for metastases? There are obviously 2 things. It works? They want to make sure their illness isn’t progressing and is at least stable. Ideally, it can shrink.
Second, and this is very important, do they tolerate it? We cannot overestimate the importance of this. Throughout my career I’ve seen therapies being rolled out in the clinic and we say, ‘It looks great on paper. It is a statistically significant impact on care and clinically significant” but the patient cannot tolerate it. Why? Because we have not adequately addressed the side effects and toxicities associated with this treatment. I strongly believe in not only evaluating whether this treatment is effective for the patient, but also how we can proactively monitor and prevent the toxicities associated with this treatment. Working with a pharmacist is very important.
Transcript edited for clarity.