(184) Patterns of Frontline Treatment Among Older Adults with Chronic Lymphocytic Leukemia or Small Lymphocytic Lymphoma

Poster Abstract:

Background: Survival for patients with CLL/SLL has improved over the past decade, largely due to novel oral anticancer agents (OAAs). Investigations utilizing population-based sources such as the Surveillance, Epidemiology, and End Results (SEER) Program indicate much of that benefit has occurred primarily in younger populations, with much more modest, or no improvement in older patient groups. The use of OACs in older adults is complicated by clinical and financial toxicities potentially compromising medication adherence and clinical outcomes. In clinical trials, patients with dose intensity (DI) >95% experienced longer median progression-free survival (PFS) compared with those with lower DI. This study utilizes data from the SEER-Medicare linkage to characterize adherence and persistence to ibrutinib among older adults with CLL/SLL.

Methods: We utilized the most recent years of data available from the SEER-Medicare linkage to describe ibrutinib adherence (using proportion of days covered, PDC) and persistence (using days until discontinuation) and identify patient-level predictors of “high” adherence (>95% PDC) during the study period: 2013-2017 (using Medicare claims from 2013-2019).

Patients with any ibrutinib claim were identified from a cohort of patients with primary diagnosis of CLL ≥66 years of age at diagnosis with continuous enrollment in both Medicare Parts A and B 12 months prior to diagnosis. To measure adherence and persistence to ibrutinib, we assigned initiation of ibrutinib as the date of the patient’s first record indicating an ibrutinib administration or prescription fill. Days supply and dosage information from prescription claims were used to construct a chart with daily entries for whether the patient had ibrutinib on-hand. To calculate 2-year PDC, the denominator was number of days during follow-up; the numerator was number of days the patient had ibrutinib on-hand. Persistence was calculated by patient’s time to first 30-day period of non-persistence to ibrutinib. Time to discontinuation was 30 consecutive days without ibrutinib on hand. We examined demographic and clinical factors associated with mortality among cohort including comorbidities, year of diagnosis, race/ethnicity, socioeconomic variables, geographic region, age, and sex.

Anticipated

Results: The number of patients receiving ibrutinib having a diagnosis of CLL/ SLL and the demographic makeup of the cohort will be reported. The percentage of patients with optimal adherence rates for the cohort (PDC>95%) and mean duration of therapy will be reported. Significant predictors of non-adherence while on treatment will be reported. Factors influencing persistence will be reported.

Conclusions: Anticipated.

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