Abstract 198P
Background
Ongoing adjuvant trials are evaluating the use of cyclin-dependent kinase 4/6 inhibitors (CDK4/6i) in combination with endocrine therapy (ET) in HR+/HER2- breast cancer (BC) to improve invasive disease-free survival (iDFS). This study assessed patient and oncologist preferences for adjuvant combination regimens.
Methods
Patients diagnosed with stage II-III HR+/HER2- BC and oncologists in the United States completed an online survey that included two discrete choice experiments (DCEs). In one DCE, respondents chose between hypothetical treatment profiles that varied by 7 attributes associated with ET (aromatase inhibitor or tamoxifen) and CDK4/6i + ET regimens: efficacy (iDFS), safety (neutropenia, alopecia, electrocardiogram [ECG] monitoring, nausea, diarrhea), and dosing schedule. In the second DCE, respondents chose between two profiles varying in CDK4/6i + ET attributes or a fixed ET only option. Hierarchical Bayes models estimated attribute-level preference weights used to compute conditional relative importance for patients and oncologists. Logistic regression models were used to identify patient factors associated with choosing ET regimens only.
Results
For patients (n=300) and oncologists (n=200) across both DCEs, improving iDFS was most important (1.5-4 times more important than the next most important attribute), followed by neutropenia and diarrhea risk for patients and oncologists, respectively. Dosing schedule, alopecia risk, and ECG monitoring were typically least important for both groups. More patients (24%) than oncologists (9%) selected ET exclusively over CDK4/6i + ET. Patient factors associated with selecting ET monotherapy included natural menopause (vs. induced/premenopausal), stage II (vs. stage III) BC, and not college educated.
Conclusions
Patients and oncologists were generally willing to accept increased risks of adverse events with combination CDK4/6i regimens in exchange for improved iDFS. However, patients placed relatively higher importance on safety-related attributes, emphasizing the need for clinicians to communicate and manage potential adverse events with patients to support them in achieving their treatment goals in early BC.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Pfizer Inc.
Funding
Pfizer Inc.
Disclosure
K. Beusterien: Full/Part-time employment, Employee of Kantar, who were paid consultants to Pfizer in connection with the development of this abstract: Kantar. E.H. Law: Shareholder/Stockholder/Stock options, Full/Part-time employment: Pfizer Inc. B. Hallissey: Full/Part-time employment, Employee of Kantar, who were paid consultants to Pfizer in connection with the development of this abstract: Kantar. M.L. Smith: Full/Part-time employment, Co-founder of Research Advocacy Network, consultant to Pfizer in connection with the development of this abstract.: Research Advocacy Network. M. Gaschler: Full/Part-time employment, Employee of Kantar, who were paid consultants to Pfizer in connection with the development of this abstract: Kantar. M.C. Maculaitis: Full/Part-time employment, Employee of Kantar, who were paid consultants to Pfizer in connection with the development of this abstract: Kantar.