Adherence of oral targeted agents in patients with B-cell malignancies

• Published in: Journal of clinical oncology Vol. 37; no. 15_suppl; p. e18301
• Main Authors: Samples, Laura S., Banjanin, Dora M., Kim, Booyeon, Graf, Solomon A.
• Format: Journal Article
• Language: English
• Published: 20.05.2019
• ISSN: 0732-183X; 1527-7755
• DOI: 10.1200/JCO.2019.37.15_suppl.e18301

Abstract only e18301 Background: Oral targeted agents (OTAs) are rapidly changing the management of B-cell malignancies (BCM) and introducing challenges in prescribing practices and communication between patients, their clinicians, and pharmacists. Emerging data suggests dose interruptions impair OTA efficacy in BCM. However, infrastructure to ensure best practices may be outstripped by increasing OTA use in some clinics. We evaluated adherence to OTAs for BCMs at the Veterans Affairs Puget Sound Health Care System to identify opportunities for quality improvement in prescribing practices and patient education. Methods: Consecutive patients treated with OTAs for BCMs from 2014 to 2018 were examined by detailed chart review and included if they used an OTA uninterrupted for ≥ 30 days. OTA adherence was assessed by 1) identification of medication gaps ≥ 8 days not attributable to medication toxicity or disease progression and 2) ReComp, a validated electronic pharmacy refill adherence algorithm in which a value of 1 corresponds with perfect adherence and deviations from 1 correlate linearly with either over- or under- supply. Logistic regression modeling assessed for independent predictors of adherence. Results: Fifty patients were evaluated and 39 met inclusion criteria. They were prescribed 42 unique OTAs, including ibrutinib, venetoclax, idelalsib, and acalabrutinib over a total of 33,655 days, with a median duration of 420 days (range 60 to 1687). Twenty-three patients (59%) had at least one medication adherence gap ≥ 8 days. Five patients (13%) had ≥ 3 eight-day gaps. The study population had a mean ReComp value of 1.02 (median 0.99, standard deviation 0.15). Medication over-supply was identified in 46% and a quarter of patients were adherent < 93% of the time. No statistically significant correlations were identified between either measure of adherence and examined factors related to socio-demographics and comorbidities. Conclusions: In our institution, a significant percentage of patients prescribed OTAs for BCMs experienced suboptimal adherence. These data identify opportunities to improve disease-related outcomes and costs. Initiatives to improve education and automated monitoring of OTA refills are under evaluation.