REAL-WORLD DATA DESCRIBING THE ROLE OF CHEMOTHERAPY IN THE TREATMENT OF HR+/HER2- MBC PATIENTS- DIVERGENCE FROM EVIDENCE-BASED MEDICINE
Feinberg B1, Kish J2, Dokubo I3, Wojtynek J3, Lord K4
1Cardinal Health Specialty Solutions, ATLANTA, GA, USA, 2Cardinal Health Specialty Solutions, Dublin, OH, USA, 3Athenex Inc., Schaumburg, IL, USA, 4Cardinal Health Specialty Solutions, San Antonio, TX, USA
OBJECTIVES Randomized controlled trials and published guidelines recommend endocrine therapy, specifically cyclin-dependent kinase 4/6 inhibitors (CDK 4/6i) in combination with either aromatase inhibitors or fulvestrant, as first-line (1L) therapy for hormone receptor-positive (HR+) human epidermal receptor2 negative (HER2-) metastatic breast cancer (mBC). Chemotherapy is reserved for patients in visceral crisis. We aimed to understand the use of 1L chemotherapy in the treatment of HR+/HER2- mBC in the U.S. post-approval of the first CDK 4/6i palbociclib in 2015. METHODS Female HR+/HER2- patients diagnosed with mBC (at least one non-diagnostic inpatient/two outpatient claims for breast cancer and one claim for lymph node/distant metastatic disease) initiating 1L treatment between 01/01/2015 and 10/31/2018 were identified in the Symphony Health administrative claims database. Regimes received in 1L were categorized as: single-agent chemotherapy (saChemo), combination chemotherapy (cChemo), and hormonal/targeted (H/T). Patient demographics, frequency of use of agents, comorbidities (Charlson components) at 1L initiation, and the proportion of patients who had not initiated second-line (2L) therapy (proxy for progression-free survival) at 6 months from 1L start of treatment (Kaplan-Meier method) were assessed. RESULTS 4317 HR+/HER- patients were identified. 1L treatment patterns/mean age: saChemo 18%/64yrs, cChemo 21%/61yrs, H/T 61%/67yrs. Comorbidities >2: saChem=6%, cChemo=4%, H/T=6%. Visceral metastasis: saChemo=23%, cChemo=19%, H/T=58%. The top 3 most frequent saChemo: capecitabine=12%, paclitaxel=11%, nab-paclitaxel=11%; cChemo: cyclophosphamide/doxorubicin=23%, cyclophosphamide/docetaxel=9%, carboplatin/paclitaxel=4%.; H/T: anastrozole=25%, letrozole=23%, fulvestrant=13%. 6-month proportion of patients not initiating 2L, saChemo: paclitaxel=94%, capecitabine=76%, docetaxel=60%; cChemo: carboplatin/nab-paclitaxel=86%, carboplatin/paclitaxel=84%, carboplatin/docetaxel=74%; H/T: letrozole/palbociclib=89%, letrozole=84%, anastrozole=82%. CONCLUSIONS Endocrine therapy is recommended by the NCCN guidelines as the treatment of choice for HR+/HER2- patients. However, chemotherapy still constitutes >40% of 1L choices since the introduction of CDK4/6i. More alarming is the continued use of cChemo for these patients. Further long term follow-up is needed to understand median time to next treatment (proxy for progression-free survival).
Conference/Value in Health Info
2019-11, ISPOR Europe 2019, Copenhagen, Denmark
Health Service Delivery & Process of Care
Disease Management, Prescribing Behavior, Treatment Patterns and Guidelines