Presenter: Kourtney D. LaPlant, PharmD, BCOP, Department of Veterans Affairs, VISN 8 Pharmacy Benefits Management, Gainesville, FL
Co-Authors: Bernadette B. Heron, PharmD, BCOP, Veterans Health Administration, Pharmacy Benefits Management Services, Hines, IL; Maria J. A. Ribeiro, MD, Atlanta VA Medical Center, Emory University School of Medicine, Winship Cancer Institute, Atlanta, GA; Mark C. Geraci, PharmD, BCOP, Veterans Health Administration, Pharmacy Benefits Management Services, Hines, IL; James Duvel, PharmD, Veterans Affairs Great Lakes Health Care System (VISN 12), Chicago, IL; Samantha McClelland, PharmD, BCPS, Veterans Affairs Great Lakes Health Care System (VISN 12), Chicago, IL; Donna Leslie, PharmD, Veterans Affairs Great Lakes Health Care System (VISN 12), Chicago, IL; Marshall Tague, PharmD, BCOP, Iowa City Veterans Affairs Medical Center, Iowa City, IA
BACKGROUND: The Veterans Health Administration (VHA) Pharmacy Benefits Management Anti-Cancer Stewardship (ACS) was established to promote consistent, high-quality, value-based anticancer drug therapy. Chronic myeloid leukemia (CML) was the initial disease of focus, because tyrosine kinase inhibitors (TKIs) account for the second highest outpatient anticancer drug use by prescription fills, with imatinib, the preferred VA formulary TKI, accounting for the highest use. After the initial process of identifying a disease-specific CML cohort was established, regional pharmacist champions performed a pilot medication use evaluation (MUE) with their respective populations to determine why second-line TKI therapy was needed in select veterans.
OBJECTIVE: To describe second-line TKI prescribing patterns among VHA patients with CML with focus on the rationale supporting the change. Data findings will help direct future ACS initiatives in CML prescribing.
METHOD: A centralized documentation process was established. Pharmacist champions from 2 Veterans Integrated Service Networks (VISNs), VISN 8 Southeastern and VISN 23 North Central regions, answered MUE questions based on chart review of their identified cohort with CML. The responses to the select data points included the documented reason(s) for switching to second-line therapy (adverse drug reaction [ADR], disease progression, identified mutation, inadequate disease response, no reason provided), prior authorized drug request completed (Yes/No), detailed adjudication rationale (if provided), ADR documented in allergy or ADR section of computerized patient record system (CPRS; Yes/No), and if prior authorized drug request approval was via an oncology pharmacy specialist (Yes/No).
RESULTS: The data were reviewed for 97 patients (VISN 8, N = 65; VISN 23, N = 38) who were identified as switching to second-line TKI therapy. The documented reason(s) for a change in the chart included 45% mild or moderate ADR, 26% resistance or inadequate response, and 19% disease progression. The prior authorized drug request forms were completed in 66% of the patients and yielded similar reasons. In all, 12 (24%) of the 49 patients with documented ADRs were recorded in the CPRS. Overall, 78% of the prior authorized drug request approvers were oncology pharmacy specialists. Dasatinib was the most common second-line therapy. Data through September 2022 indicate that 30% of the patients received third-line or later therapy.
CONCLUSION: The results of this pilot indicate that, despite variable geography, mild-to-moderate ADRs are the most common reason that patients with CML were switched to second-line therapy, followed by resistance or inadequate response in the first-line setting, and disease progression. Despite ADR documentation being the most frequent reason for adjudication, most of these events were not documented as ADRs in the patient chart. Dasatinib was the most common TKI used in the second-line setting, followed by nilotinib. Most prior authorized drug request approvers were oncology pharmacy specialists.
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