Presenter: Jodi Taraba, PharmD, MS, BCOP, Breast Clinical Pharmacist, Mayo Clinic, Rochester, MN
Co-Authors: Allison Golbach, PharmD, The University of Kansas Health System, Kansas City, KS; Matt Smith, PharmD, Mayo Clinic, Rochester, MN; Kristin Mara, MS, Mayo Clinic, Rochester, MN; Karthik Giridhar, MD, Mayo Clinic, Rochester, MN
BACKGROUND: The use of cyclin-dependent kinase (CDK)4/6 inhibitors in combination with endocrine therapy for patients with advanced hormone receptor (HR)-positive, human epidermal growth factor (HER)2-negative breast cancer is rising.1-5 Managing oral oncology agents remotely, using a patient-centered model, was challenging in our previous practice. Our group developed a pharmacist-led, multidisciplinary virtual clinic to improve the management of patients who are receiving CDK4/6 inhibitors.
OBJECTIVES: To evaluate the adherence to recommended laboratory monitoring in patients using palbociclib therapy; to identify areas for optimization, including the development of a pharmacist-led CDK4/6 inhibitor virtual clinic; and to assess the impact of this clinic on adverse events, adherence, laboratory monitoring, and the identification of drug–drug interactions.
METHOD: This study included 2 cohorts, a retrospective cohort and a prospective cohort. The retrospective cohort included patients with HR-positive, HER2-negative breast cancer who initiated palbociclib therapy between May 8, 2018, and June 4, 2019; were aged ≥18 years; and had a diagnosis of advanced or metastatic breast cancer. The prospective cohort included patients receiving a CDK4/6 inhibitor—palbociclib, abemaciclib, or ribociclib—who were enrolled in the virtual clinic between May 1, 2020, and April 10, 2021. For both cohorts, the data were collected for up to the first 6 cycles of therapy. The primary outcome was the rate of adherence to recommended CDK4/6 inhibitor therapy, by laboratory monitoring, defined as laboratory blood draws every 2 weeks for the first 2 cycles and before the start of each cycle thereafter ± 3 days. The secondary outcomes included the rate of medication adherence, as reported by the patient, and assessment of potential drug interactions.
RESULTS: Patients managed by the virtual clinic were contacted, primarily via phone, every 2 weeks for the first 2 months, then monthly thereafter. These virtual visits included review of laboratory test results, medication adherence, adverse events assessment, medication reconciliation, and screening for drug interactions. Laboratory tests were appropriately done at 462 of 541 time points in the 81 patients in the retrospective cohort, and at 128 of 139 time points in the 28 patients in the prospective cohort (85.4% vs 92.1%; P = .038). The patient-reported adherence to the prescribed medication was more than 99%. A total of 38 potential drug therapy problems were identified. The interventions included patient education during therapy administration, thereby increasing adherence, symptom management, drug–supplement interactions, and monitoring of QT interval prolongation.
CONCLUSION: The implementation of a pharmacist-led virtual clinic significantly improved adherence to laboratory testing in patients receiving CDK4/6 inhibitor therapy and is now a sustained model in our clinical practice. The development and implementation of interactive care plans to use technology for the management of patients receiving CDK4/6 inhibitors is ongoing.
- Finn RS, Martin M, Rugo HS, et al. Palbociclib and letrozole in advanced breast cancer. N Engl J Med. 2016;375:1925-1936.
- Turner NC, Slamon DJ, Ro J, et al. Overall survival with palbociclib and fulvestrant in advanced breast cancer. N Engl J Med. 2018;379:1926-1936.
- Hortobagyi GN, Stemmer SM, Burris HA, et al. Ribociclib as first-line therapy for HR-positive, advanced breast cancer. N Engl J Med. 2016;375:1738-1748. Erratum in: N Engl J Med. 2018;379:2582.
- Slamon DJ, Neven P, Chia S, et al. Phase III randomized study of ribociclib and fulvestrant in hormone receptor–positive, human epidermal growth factor receptor 2–negative advanced breast cancer: MONALEESA-3. J Clin Oncol. 2018;36:2465-2472.
- Goetz MP, Toi M, Campone M, et al. MONARCH 3: abemaciclib as initial therapy for advanced breast cancer. J Clin Oncol. 2017;35:3638-3646.