David J. Andorsky, MD

A retrospective study evaluating patients with chronic lymphocytic leukemia or small lymphocytic lymphoma (CLL/SLL) treated with a Bruton tyrosine kinase (BTK) inhibitor between January 1, 2020, to April 30, 2023, in The US Oncology Network highlighted the shifting treatment landscape of BTK inhibitors, according to David J. Andorsky, MD.

Findings showed that while patients with CLL/SLL decreased their use of ibrutinib (Imbruvica) during the observation period of the study, the use of acalabrutinib (Calquence) and zanubrutinib (Brukinsa) increased. Through the evaluation of social determinants of health (SDOH), researchers observed similarities across the treatment sequence subgroups.

To assess patients' treatment patterns and SDOH, the study included 2,082 patients in a large network of community oncology practices. Patients were a median age of 73 years, 61.9% of patients were male, 73.5% were White, 35.0% were stage 0-I, and the median follow-up among those enrolled was 14.1 months. A total of 8.7% (n = 182) across the subgroups were observed to receive a subsequent BTK inhibitor. In 2020, 597 received a BTK inhibitor and among these patients, 62.3% (n = 372) received ibrutinib and 1 patient received zanubrutinib. Then, 206 patients received a BTK inhibitor in 2023, including 14 (6.8%) and 59 (28.6%) patients who received ibrutinib and zanubrutinib, respectively.

Among these patients in 2023, 137 (95% CI, 5.6-7.7) lived in rural locations. Low socioeconomic status (SES) based on state and national indicators was seen in 361 (95% CI, 15.7-19.0) and 125 (95% CI, 5.0-7.1) patients, respectively. These findings were similar across the subgroups. Medicare was the insurance coverage used by the highest proportion of patients (42.1%; 95% CI, 40%-44.3%). This was followed by managed Medicare (24.4%; 95% CI, 22.6%-26.3%).

Further, a statistical difference was noted between the treatment regimens for patients in rural and urban settings (P <.01), but not for state area deprivation index (ADI; P =.52), national ADI (P =.36), or Medicaid insurance coverage compared with all others (P =.18).

These data suggest that the SES and Medicaid do not influence prescribing patterns of BTK inhibitors. However, they found that rural/urban status show differences. Further real-world research is needed to evaluate the impact of SDOH choice of treatment, treatment switching, and more.

Hairy cell leukemia, 3D illustration. It is a hematological malignancy, chronic lymphocytic leukemia, with accumulation of abnormal B lymphocytes: © Dr_Microbe - stock.adobe.com

In an interview with Targeted Oncology^TM, David J. Andorsky, MD, medical oncologist and hematologist, Rocky Mountain Cancer Centers, and associate chair, US Oncology Hematology Research, discussed real-world findings from a study which evaluated BTK inhibitors in adult patients with CLL/SLL.

Targeted Oncology: Can you give an overview of the research?

Andorsky: This was a real-world medicine study of patients with CLL/SLL who started therapy on a BTK inhibitor. BTK inhibitors are 1 of the more commonly used targeted therapies for CLL. There are 3 that are FDA-approved now: ibrutinib, acalabrutinib, and zanubrutinib. We pulled about 2000 patients from our patient database to look at patterns of care, which BTK inhibitors were prescribed, whether patients switch from 1 to the other,. Then for this study, did social determinants of health have an impact on which therapy patients got?

What should the community oncologist know about these three approved agents?

The BTK inhibitors have been a major leap forward in the treatment of CLL. Even 5 years ago, there were still a lot of patients who were getting chemotherapy as their first line of treatment. Chemotherapy works perfectly well, but it obviously is toxic. Then, a number of studies came out showing that BTK inhibitors were superior [compared with] chemotherapy regimens, and in fact, that they had fewer [adverse] effects and work better. They're 1 of the most commonly used and standard first-lines of therapy for CLL.

What's important to know about the patterns of care with BTK inhibitors in the community setting?

We observed 2 things in this publication. The first was that over time, there was less use of ibrutinib, which was the first BTK inhibitor on the market, and more use of the second-generation inhibitors, acalabrutinib and zanubrutinib. I think this is a positive development because the newer drugs are more specific for the BTK protein, they have fewer [adverse] effects on average, and they are probably equally efficacious. But the [adverse] effect profile matters a lot to patients because people want to have these drugs for months, if not years, so that was 1 temporal trend we observed from 2020 through 2023.

The second thing we observed is that there really was not a big impact of the social determinants of health on which BTK inhibitor patients received. You might have thought that patients who live in rural environments or economically deprived environments or had a government payer maybe would get inferior treatment, or at least an earlier treatment in the form of redundant but we didn't see that. We really saw that there was no association there, which I took to mean that patients were getting the treatment that they and their doctor thought was the right treatment for them.

For community oncologists, what are the key takeaways from this research?

Although social determinants of health are very important for all practicing physicians, bear in mind how they might be impacting their patients' experience and their access to health care. At least in our network [and] in our population of patients, it didn't seem to have a major impact. That is reassuring. I think we need to focus on providing the best possible therapy for our patients.

What else in this space needs to be further evaluated?

This was just the first publication from this project. We're hoping to look among the patients that switch from 1 BTK inhibitor to another. What were the reasons for that? Was it financial or tolerance? I think we could also look at outcomes, like how long patients were on different therapies for, how long until their next line of therapy or overall survival, things like that, [and see] whether there were any associations either with the drug that they were given or the social determinants of health. Those are things that we're hoping to look at in future studies.

In your own practice, what are some of the factors that contribute to giving the different types of BTK inhibitors?

In my own practice, I've largely gotten away from using ibrutinib. I think it was a great breakthrough. As a first class, it really changed the field, but acalabrutinib and zanubrutinib, by experience, tend to be better tolerated. I typically would start with 1 of the 2 of them. If 1 of them is less expensive for the patient, I'll often go with that. That depends on the patient's insurance and their pharmacy benefits and whatnot. Sometimes the patient is not tolerating 1, so I'll switch to the other. It's nice to have options. Sometimes if you have only 1 drug in a class, we do everything to keep them on it, even if they're having a lot of [adverse] effects. It's nice to have 3 options so we can change patients who have different therapy if they're not tolerating 1.

REFERENCE

Andorsky DJ, Zackon I, Wilson TW, et al. Recent patterns of care with BTK inhibitors and distribution of social determinants of health among patients with CLL/SLL in the US community setting. Blood (2023) 142 (Suppl 1): 2413. doi:10.1182/blood-2023-172880