Patterns of Care With BTK Inhibitors for CLL/SLL in the Community Setting With David Andorsky, MD
At the recent American Society of Hematology (ASH) Annual Meeting in San Diego, Dr. David Andorsky, MD, a Clinical Hematologist and Medical Oncologist at the Rocky Mountain Cancer Centers in Boulder, Colorado, presented his research and observations regarding patterns of care with Bruton tyrosine kinase (BTK) inhibitors and the distribution of social determinants of health among patients with chronic lymphocytic leukemia or small lymphocytic lymphoma (CLL/SLL). In this interview, he further discusses how the treatment landscape of CLL/SLL has changed with the introduction of BTK inhibitors and his next steps for this research.
Oncology Data Advisor: Welcome to Oncology Data Advisor. Today, we're here at the ASH Annual Meeting with Dr. David Andorsky. Thank you so much for your time today. Would you like to introduce yourself and your research interest?
David Andorsky, MD: Yes. I am a Clinical Hematologist and Medical Oncologist at the Rocky Mountain Cancer Centers in Boulder, Colorado. I've been with the group for 13 years. I'm also very involved in hematology research, particularly in lymphoma, and I sit on the Sarah Cannon Research Institute Lymphoma Executive Research Committee.
Oncology Data Advisor: Awesome. Thank you for that. To start, I wanted to ask you, how has the treatment landscape of CLL/SLL shifted with the introduction of BTK inhibitors?
Dr. Andorsky: Well, I think it's made a huge difference. I was just preparing a talk a few months ago to give to some primary care doctors, and I was updating some slides that I had from 2019. I looked at my slide that had guidelines for first-line therapy, and I literally had to cross every single line out and put something else in. It's really changed a lot.
When I was a fellow, we were giving a lot of chemotherapy, a lot of high-dose steroids, and rituximab. By the time I joined the practice, we were giving a lot of fludarabine, cyclophosphamide, and rituximab (FCR) and bendamustine/rituximab, which were very effective therapies but had a lot of toxicity, including some late toxicity. And then, the BTK inhibitors and venetoclax came onto the scene, and things have really changed a lot.
Now, I can sit down with a patient and say, "You've got this condition. We've got to treat it." They're incredibly effective treatments. They have very few side effects for most people, and this is something that we hope that you're going to live with and not die from.
Oncology Data Advisor: For the study that you're presenting with your abstract, could you give us a brief overview of the study and the results you presented?
Dr. Andorsky: This is a real-world medicine study of a large cohort of patients with CLL/SLL in the US Oncology practices. We are beginning to look at treatment patterns and also social determinants of health, which has become kind of a hot topic in medical research.
So, we used our electronic medical record to find about 2,000 patients who started on a BTK inhibitor during the index period. We looked at whether those patients switched to a different BTK inhibitor. About 8% of patients switched, and the vast majority stayed on the same one they had started on.
We saw that over time, more of the second-generation BTK inhibitors, acalabrutinib and then zanubrutinib—which was just approved in January this year—have comprised a larger portion of the BTK usage, which you'd expect. And then we also looked at whether social determinants of health were correlated with which medication patients were receiving. We looked at rural versus urban status. We looked at people who lived in economically deprived areas, both on the state and national level. And we also looked at payer mix, Medicaid, Medicare, or commercial payers.
We actually didn't find much in the way of associations, which I found to be reassuring because it means the patients are getting the care that they need, that their doctor thinks they need, regardless of where they happen to live or who the payer is. There was a statistically significant difference in prescriptions in rural versus urban. Interestingly, in the rural communities, rural zip codes, we had more patients getting second-generation BTK inhibitors than ibrutinib.
I'm not sure of the explanation for that. They were relatively small numbers only. I think 5% or 10% of the patients in the study were in a rural zip code. So, we might want to look at that a little bit further. But that's kind of the summary of the findings.
Oncology Data Advisor: It seems like you're touching a lot of bases with this study, but were there any limitations that you experienced?
Dr. Andorsky: So, a major limitation of any real-world medicine is that it's all retrospective, and you're taking more of a bird's-eye-view of the data and can't really get into detail with what's going on with an individual patient or patient cohort. So, those are some sort of standard limitations of real-world medicine, but in terms of the findings that we have, I think we feel pretty good about those.
Oncology Data Advisor: Definitely. Does your team have plans to further evaluate this study or going into a further phase 3 trial?
Dr. Andorsky: Yes, absolutely. Well, it's not really a trial. It's more of, again, observation and what we call outcomes research. So, this is really just the first publication from this project. We're looking at other things, such as those patients that did switch from one BTK inhibitor to another. Why did they switch? We're going to hopefully look at real-world evidence of progression-free survival or time of the next treatment end points to see how that stacks up with what we've seen in the clinical trial, and then again if there are any interactions with social determinants of health based on those parameters.
Oncology Data Advisor: Definitely. And then, final question that I have for you is just kind of curiosity. Why is it vital that studies like this are conducted to better understand evolving treatment landscapes such as with BTK inhibitors?
Dr. Andorsky: This is a great question. I think the question is, really, what's the function and value of real-world medicine in the research landscape? So, we obviously depend on rigorously conducted clinical trials to study new agents, figure out how to get them approved, see whether they work or not, and then, hopefully, lead to new advances in therapy.
The difficulty is clinical trials are very controlled environments. You have patients that are highly motivated to find those trials and doctors that are highly motivated to put them on. Patients in clinical trials across the board in oncology tend to be younger, less diverse, and probably from a higher socioeconomic status.
That last one, I'm not 100% sure about, but at my intuition, that's likely the case. And so the question is, once you get a drug out into the real world where you have patients that are older, more diverse, maybe economically disadvantaged, and also being treated in much different environments than where clinical trials are conducted, you always wonder and want to know, can we reproduce the results of those studies or not? And are certain populations not benefiting?
In a clinical trial, you're limited by the patients who walked in the door. If you want to know patients in rural environments versus urban or economically deprived areas, you're really going to have to do this kind of real-world medicine to answer those types of questions. So, I look at it as a real companion to the clinical trials to really see how these new treatments play out in the real world.
Oncology Data Advisor: Definitely. That's awesome. Thank you so much for your time today, and thank you for your research and your passion on this topic. Thank you so much, Dr. Andorsky.
Dr. Andorsky: My pleasure. Good to be here.
About Dr. Andorsky
David Andorsky, MD, is a Clinical Hematologist and Medical Oncologist at the Rocky Mountain Cancer Centers in Boulder, Colorado. As well, he sits on the Sarah Cannon Research Institute Lymphoma Executive Research Committee. Dr. Andorsky's research focuses on hematologic malignancies such as lymphoma, leukemia, and multiple myeloma, in addition to his practice including breast, colorectal, lung, and urological cancers.
For More Information
Andorsky D, Zackon I, Wilson T, et al (2023). Recent patterns of care with BTK inhibitors and distribution of social determinants of health among patients with CLL/SLL in the US community setting. Presented at: 2023 American Society of Hematology Annual Meeting. Abstract 2413. Available at: https://ash.confex.com/ash/2023/webprogram/Paper172880.html
Transcript edited for clarity. Any views expressed above are the speaker's own and do not necessarily reflect those of Oncology Data Advisor.