During Breast Cancer Awareness Month, Pharmacists Can Do More Than Wear Pink

In an interview with Pharmacy Times, Bob Luschen, PharmD, an oncology pharmacist at Cancer Treatment Centers of America, discussed the growing role of pharmacists in breast cancer and recent updates that pharmacists should be aware of. Although October is Breast Cancer Awareness month, he said pharmacists are involved in this space year-round and always have the opportunity to educate patients.

Aislinn Antrim: Hi, I'm Aislin Antrim with Pharmacy Times. October, of course, is Breast Cancer Awareness Month, and I'm here today with Bob Luschen, PharmD, of Cancer Treatment Centers of America to discuss the breast cancer space and pharmacists’ growing roles in it. So, breast cancer has been developing really quickly in recent years. Are there any key shifts or developments in this space that you would like to highlight?

Bob Luschen, PharmD: Absolutely, and thank you so much for having me. The biggest developments that we're seeing in the past few months have to do with looking as closely as possible as we can at the specific presentation of a patient's disease. And if we can study more specifically, then we can have treatment options that are tailored more precisely to a patient's presentation.

One drug, fam-trastuzumab‑deruxtecan-nxki, trade name is Enhertu, had a recent indication addition to its label for metastatic HER2-low breast cancer. So, in the past, historically, we'll look at hormone receptor positivity, estrogen, and progesterone receptors along with HER2 positivity to try and drive treatment choices. And we would break down HER2-positive or HER2-negative by use of staining the tissue on pathology or sending it out for more precise molecular testing. What we found with this most recent indication for Enhertu is patients who we previously thought were either maybe a little HER2- positive or not HER2-positive enough on pathology to really see a difference from anti-HER2 therapy were responding to Enhertu with increased progression free and overall survival versus chemotherapy. So, that's a way to be more precise in treatment.

Similarly, sacituzumab govitecan-hziy is another antibody drug conjugate. This one has a target of Trop2 as opposed to a target of HER2 and it was previously approved for triple-negative breast cancer. However, there's been some recent encouraging data for use in hormone receptor-positive HER2-negative disease. So, that means more patients. And this is for patients who have been heavily pretreated with multiple prior lines of therapy. But we've seen some positive data in terms of its activity in those patients.

And then the big one that we'll probably talk about quite a bit in recent months is the addition of immune checkpoint inhibitor therapy for triple-negative breast cancer. So, the use of pembrolizumab, trade name is Keytruda. In combination with chemotherapy for triple-negative breast cancer patients with a combined prognostic score, or CPS, of 10 or greater, it showed increased progression free survival. All that's happened in the past few months and they're all treatment changing and paradigm shifting options for our patients.

Aislinn Antrim: Wonderful. That's all really exciting. And there have been some particularly good developments for metastatic breast cancer, which you touched on. This has historically been really challenging to treat and has had very challenging outcomes. So, are we seeing a shift towards kind of more treatable metastatic breast cancer?

Bob Luschen, PharmD: So, what we're seeing is multiple options depending on that patient's specific presentation, down to mutations in the cancer itself. So, we mentioned the use of fam-trastuzumab deruxtecan-nxki for HER2-low metastatic disease, we mentioned sacituzumab govitecan-hziy for hormone receptor-positive HER2-negative metastatic disease, and then pembrolizumab plus chemo for triple negative.

We're also seeing targeted options for patients with specific mutations. So, there's oral options like alpelisib, which is an oral medication that targets patients with disease that has a mutation in PIK3CA. We're also looking at patients who have BRCA1 and 2 mutations, which I know is a major focal point especially when we're talking about screening and genetic counseling. However, patients with that type of mutation present in the actual disease, the tissue, were candidates for use of talazoparib or olaparib, which are PARP inhibitors. We also look at mutations in NTRK. Patients who are positive for that mutation would be eligible for medications like entrectinib and larotrectinib. So, all these different options.

The key, really, when it comes to treatment of metastatic disease, is sequencing. The more we know about a patient's specific presentation, the better we're able to sequence these treatments in a way that maximizes how effective they are for that patient's disease.

Aislinn Antrim: Absolutely. Historically, experts believed that breast cancer was immunologically silent. But some newer studies have found that immunotherapy could potentially be effective, particularly in HER2-positive and triple-negative breast cancer. Can you discuss this development?

Bob Luschen, PharmD: Absolutely. So, you are right. There's unfortunately not been a huge wave of the use of immunotherapy, and when I'm saying immunotherapy in this portion, I'm talking specifically about immune checkpoint inhibition. So, pembrolizumab is what we've discussed previously. KEYNOTE-522 was the name of the trial that looked at pembrolizumab in combination with chemotherapy for treatment of metastatic triple-negative breast cancer with a CPS of 10 or greater. And when we say CPS, the way to understand that is the level of mutational burden that that disease has in that specific presentation for that patient. And so that's really what we're looking to fight against, or what allows us to have pembrolizumab or immune checkpoint inhibitors as a treatment option for these patients, is that higher degree of mutational burden for their disease. There's also options available for single agent immune checkpoint inhibitor therapy for these patients. If they have a high degree of tumor mutational burden as defined as either that CPS 10 or greater or a high degree of what we call microsatellite instability, which is something that we'll look at with advanced testing, that is regardless of tumor type. And it can be a treatment option as single agent therapy for pre-treated patients who are, frankly, running out of other options. Thankfully, we do have good data in that subset.

Aislinn Antrim: Wonderful. Are there any pipeline treatments that pharmacists should be really keeping an eye on?

Bob Luschen, PharmD: Sure. So, there have been certain options that are now moving from phase 2 into phase 3 studies, and I mentioned a couple of the real big, long names at the beginning. So, I should clarify kind of what we're talking about with that drug class between fam-trastuzumab deruxtecan-nxki, sacituzumab govitecan-hziy, those are both antibody drug conjugates. And that is a monoclonal antibody which is designed to target a very specific protein on the surface of the cancer cell. And when it is bound to that protein it’s brought into the cancer cell. There's a cleaving of the linker between the antibody and a chemotherapeutic drug, at which point that chemo drug can take its effect inside the cancer.

So, there's a couple of other options that are in phase 3 studies right now, both of which are anti-HER2 targeted monoclonal antibody drug conjugates. One of them is tisotumab vedotin-tjtv, another one is trastuzumab duocarmazine. So, they're both in phase 3 development. There's one other that has a research study name of ARX 788, currently involved in a basket trial, which is defined as multiple drugs available for multiple different disease presentations, depending on the specific presentation of that disease for that patient.

In addition to the antibody drug conjugates, there's one other medication that is in development for those patients who have the PIK3CA mutation. It's called tenalisib, it had some good interim data for the phase 2 trial which is underway, and hopefully will be able to move forward in terms of research potential.

In terms of pharmacotherapy, one more class that is in development right now is a group that goes by the name of protac degraders. So, that's specific to hormone receptor-positive, HER2-negative disease as another potential agent to target the hormonal source of disease progression that happens for those patients outside of drugs, and those types of targets. There's also a lot of research being done right now in the use of circulating tumor cells and circulating tumor DNA as a way to look forward to a patient's potential for progression and overall survival. It's where a lot of research is focused right now when it comes to not just screening but also assessing how well a patient has responded to therapy, and how likely they are to have longer progression free survival and overall survival. However, there's still more research to be done there before we can use it as a real prognostic indicator.

Aislinn Antrim: Wonderful. How are pharmacists involved in breast cancer treatment overall? And what unique insights or perspectives do they bring to the care team?

Bob Luschen, PharmD: Pharmacists are involved in both the inpatient and infusion settings as well as outpatient, with the dispensing of oral chemotherapy and dispensing of medications used as supportive care. When it comes to being a part of the care team for the breast cancer patient, pharmacists can really shine in the area of supportive care. That's regardless of which regimen we're using, regardless of the care setting where the pharmacist finds themselves. We have a unique perspective on how medications can create toxicity and how we can also use medications to get in front of or to help mitigate toxicity to keep patients’ performance status at a level where they can continue on with therapy towards the goals that they have set for themselves.

In terms of the care setting, within the clinic pharmacists are well positioned to help clarify complicated regimens. There are certain regimens, especially when we're looking at combinations of chemotherapy, immunotherapy, oral therapies, where they may have IV medication weekly or every other week, they may have some medications weekly, some every 3 weeks, some in combination with oral regimens where they need a certain level of monitoring. Pharmacists can really help clarify those complicated situations. Of course, a cornerstone of pharmacists’ involvement is drug-drug interaction checking, counseling on all those interactions and what to look out for, as well as assisting with monitoring considerations. A lot of these drugs have specific types of imaging or regular monitoring—as an example, monitoring left ventricular ejection fraction for patients who are receiving an anti-HER2 monoclonal antibody. We've already talked about a couple of them during the course of our conversation here. That has to happen on a regular interval. And that is something that requires monitoring from everyone in the team, pharmacists included. There are lots of ways for pharmacists to be involved in the care of the breast cancer patient.

Aislinn Antrim: Absolutely. You mentioned oral therapies, and a lot of the logistics that go along with oral therapies and all of the different options is communication. So, how are pharmacists really positioned to communicate with patients and be the go between for them and physicians?

Bob Luschen, PharmD: Absolutely. That's a big part of pharmacist training, is being able to understand the clinical scenario. Being able to communicate effectively with providers, with nurses, have members of the clinical staff, and then being able to take that information, turn it into something that's practical and useful for the patient and caregiver. And so that is especially important when we're talking about adverse drug reactions, whether we're talking about infused medications, oral regimens. Wherever we're located and situated to counsel that patient and caregiver, it is a unique skill set for the pharmacist to be able to convey that information in a way that makes sense, where the patient can use it.

In terms of practical considerations, a lot of these medications, especially talking about monoclonal antibodies, will have biosimilars—if not already, they will soon. That's been a big impact in terms of the marketplace for medications and how we have to arrange care for our patients and explaining what a biosimilar is, how it plays a role in that patient's care, and what they need to know about it. It's a way that pharmacists can definitely ease fears and solve issues of confusion or concern. Also, with the advent of immunotherapy in the treatment of breast cancer patients, there's a big difference in terms of toxicity between chemotherapy and immune checkpoint inhibition. Pharmacists are well situated to educate not just the clinical staff but also the patient and caregiver on the difference between those toxicities, how we get out in front of them, how we can best address them to keep the patients safe. And if at all possible, keep the patient on a therapy that would be very effective for them in the long run.

Aislinn Antrim: Wonderful. As more and more treatments become oral and potentially shift into the outpatient environment, how are pharmacists more important than ever to ensure that patients are really adherent to challenging and complicated regimens?

Bob Luschen, PharmD: For oral regimens, a lot of them are going through specialty pharmacies. However, for the supportive medications that are hand-in-hand with those oral regimens going through retail pharmacy, [there are] lots of opportunities for pharmacists to be involved in counseling patients on what to expect, when to use medications that are intended for support around their therapeutic regimen, and when to reach out to their clinic team for support. Also, but in the background, a lot of these oral chemotherapy regimens are very tightly regulated either from the manufacturer or through insurance. And so, there are REMS programs, there's prior authorization. There's lots of that type of infrastructure that a pharmacist is very well situated to help a patient or caregiver navigate through, especially when initiating treatment that can be a huge cause of delays and care. Pharmacists are very, very well situated to assist patients and caregivers. Absolutely.

Aislinn Antrim: What do effective transitions of care look like and how are pharmacists involved in this process?

Bob Luschen, PharmD: The biggest barrier to these types of transitions in my experience is communication, or the lack thereof. Pharmacists can definitely assist in that scenario, especially if we're talking about transitioning between regimens while communicating between the clinic team, the provider, the nurses who are involved in documentation sometimes, and assisting with getting prescriptions to the right place. And also working with the insurance companies or, if you’re in a facility where you have authorization teams or other specialists working with that team, to make sure they have all the information they need when it comes to that transition. There's a lot of education also that takes place in those transitions, not just with the new regimen for the patient and the caregiver, but also sometimes in regard to the medications that are involved. We just mentioned medications that are in the pipeline that will hopefully one day become viable options for our patients. We have to educate around those to keep everyone safe, from the provider writing scripts to the nurse administering the medication who's never seen it before, to the patient who is nervous about a new line of therapy. Education, as mentioned before, is something that pharmacists are very well situated to assist with. And just like we mentioned previously, supportive care. Whenever we're transitioning care, or transitioning regimens, that supportive care environment may change as well. And so that's something pharmacists can definitely assist with.

Aislinn Antrim: Wonderful. The broader public is typically more aware of breast cancer prevention during the month of October. There's many campaigns about it. Can you discuss how pharmacists in all environments can help educate patients about signs and symptoms of breast cancer year-round, and not just during this one month?

Bob Luschen, PharmD: Absolutely. Besides wearing pink, which is helpful, pharmacists can stay educated to update themselves, if we're going to be in that position to educate patients. To be a source of reliable health care information as effective health care communicators, we have to be educated as well. So, staying up to date on epidemiology, on risk factors, signs and symptoms via continuing education is something that we have to prioritize as health care professionals. One possible tactic is to designate October as the month where you do a breast cancer-focused continuing education. In the state of Georgia, its license renewal time. But anytime is appropriate to continue to increase your knowledge base, even if it's something that you're not interacting with on a daily basis.

Encouraging screening for appropriate age groups and demographics [is also important]. If we are aware of signs and symptoms, we can educate to them. However, we also have to educate on when to contact a clinic team. If you're experiencing specific toxicities, we need to know when to educate our patients and our caregivers on when to pull the trigger on a screening, when it's time to go get that checked out. Also, participating in local awareness events. You know, during October, of course, there's more breast cancer focused events the Susan G. Komen walk and other types of dedicated events. There's also Relay for Life, which is an event that happens in local areas all through the course of the year with the American Cancer Society. There's lots of ways for pharmacists to get involved with awareness and education.

Aislinn Antrim: Wonderful. Well, October is also American Pharmacist Month, so we're asking all of our guests, what is the value of the pharmacist to you and how are you celebrating this month?

Bob Luschen, PharmD: Yes, happy Pharmacy Week also, this is taking place on October 20. Happy belated Pharmacy Technicians Day. Pharmacists are the medication experts. That's our wheelhouse. That's how we're trained. We are an essential part of the health care team in all care settings, it doesn't matter if you're institutional, if you're in outpatient infusion, in the retail setting, compounding, managed care. There's so many ways pharmacists are involved in the furthering of health care. In this country, we bridge the gap in terms of medical information between clinicians and the patients and caregivers. We are a source of information and thereby a source of peace of mind for our fellow professionals and for the patients whom we serve. We're a defense against harm from medication errors because like it or not, we're all human. And so, we're an essential part of that process that avoids one of the most common causes of health care-related injury in this country. And we're a trusted member of the community, beyond just our expertise in health care provision.

I'm happy to be celebrating with the staff here at CTCA. We've been very lucky to have meals together, to have some activities that we're able to take part in together, to celebrate one another. Unfortunately, we don't get the chance to do as often as we'd like, you know, everyone stays very, very busy, of course. But it's all pharmacists, pharmacy technicians, and pharmacy staff who are able to take part.

Thank you. You don't hear it enough. I really want you to know that you're appreciated, that what you do matters. So, keep up the good work, keep learning, and happy Pharmacy Week and Pharmacy Month.