Real-World Evidence on Shift in Treatment Practice and Adoption of Novel Agents for Patients with Chronic Lymphocytic Leukemia in the United States

Introduction: Clinical availability of highly effective novel agents (including Bruton tyrosine kinase [BTK] and B-cell lymphoma 2 [BCL-2] inhibitors) is rapidly altering the therapeutic landscape of chronic lymphocytic leukemia (CLL) necessitating a review of treatment guidelines. However, there is limited real-world data to validate if the availability of these novel agents has translated to a true shift in treatment paradigm for patients treated in the community. As the majority of CLL patients are treated in non-academic community-based settings, we investigated the clinical adoption trends of commercially available FDA approved novel agents for treatment of CLL patients. In addition, given that the COVID-19 pandemic led to major alteration in clinical oncology practices, we further studied if this contributed to an alteration in the selection of therapeutic agents resulting in changes of CLL treatment patterns and the utilization of novel agents in the real-world setting. Thus, the objectives of this study were to examine the utilization pattern of various CLL therapies, as well as evaluate the pattern of adoption of novel agents for treatment and the impact of COVID.

Methods: A retrospective observational study was conducted using the Flatiron Health database that comprised EHR-derived de-identified data. Adult patients (≥18 years) with newly diagnosed CLL from January 2014 to May 2021, with no prior treatment and who were continuously enrolled for at least 6 months before and 3 months after the index date, defined as the first date of CLL/SLL diagnosis were included. Treatment regimens were classified into seven mutually exclusive categories: bendamustine-based chemotherapy, other chemotherapy, anti-CD20-based therapy, ibrutinib, idelalisib, acalabrutinib and venetoclax. Further treatment categorization included chemotherapy vs. targeted therapy, and traditional IV vs. novel oral agents. The impact of the pandemic was examined by comparing the pre- and post-COVID cohorts (defined as 15 months pre- and post- of March 1, 2021). Descriptive analyses were conducted to examine the frequency of use of treatment regimens by quarter in each year, line of therapy and between different age, gender, US geographical region, insurance status, and race/ethnicity subgroups. Multivariable regression was conducted to examine factors associated with the likelihood of adoption of novel and oral agents. Statistical significance was determined at a p-value of less than 0.05.

Results: A total of 3,037 newly diagnosed CLL patients (median age =73) were included in the study. Over half were male (62.3%), white (74.6%) and commercially-insured (54.1%). Patients were primarily treated in community practices (92%). Overall, a significant trend in adoption of novel agents was observed throughout the years following their approval (Figure 1A). Across the evaluation period, a significant decrease in chemotherapy use was observed from 61.3% (quarter 1, 2014) to 20% (quarter 2, 2021) in favor of targeted therapy as first-line therapy (Figure 1B). In contrast, the utilization of novel oral agents (vs. traditional IV agents) for first-line therapy increased from 9.5% to 70.9% for the same period (Figure 1C). Similar trends were observed for second-line and third-line therapies. Encouragingly, this change in treatment patterns was adopted comparably in all sociodemographic subgroups with no evidence of disparity. While there was no statistically significant difference between the pre- and post-COVID treatment landscape, the adoption of target and novel oral agents has been more pronounced with the COVID pandemic.

Conclusions: Results from real-world data suggest that there is a clear shift towards the adoption of novel therapies with preference given to targeted agents and oral therapies in the US since 2014. Further research examining real-world outcomes associated with treatment regimens are needed to inform decision makers.

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