HER2 REAL: Real-World Treatment Patterns in HER2-Positive Unresectable LA/MBC

The objective of the multicountry, retrospective HER2 REAL study (NCT04857619) was to assess treatment practices and treatment outcomes in patients with HER2-positive unresectable locally advanced or metastatic breast cancer (LA/MBC) in the Asia-Pacific (APAC) and Latin America regions. Results of the interim descriptive analysis (demographics, clinical characteristics, and treatment patterns) of the APAC cohort were presented at the 2023 ASCO annual meeting.

A medical chart review identified adult patients diagnosed with HER2-positive unresectable LA/MBC who were diagnosed since January 1, 2017, or reimbursement of trastuzumab emtansine (T-DM1), had ≥12 months of follow-up data from diagnosis, and were treated with ≥1 lines of therapy. Date of data cutoff was June 30, 2022.

A total of 763 patients were identified; of these, 370 patients from the APAC region (Hong Kong, Korea, Singapore, and Taiwan) were eligible for the interim analysis. In the APAC cohort, median age was 55 years and median time from initial BC diagnosis to relapse was 2 years; 210 (57.1%) patients were postmenopausal. The majority had ductal carcinoma (61.4%), visceral metastasis (68.9%), or nonvisceral metastasis (69.7%); 21.6% had central nervous system metastases.

In terms of treatment pattern, the majority of patients (76%) received HER2-directed therapy in the first-line setting (mainly trastuzumab- and pertuzumab-based therapy) and in the second-line (81%; mainly T-DM1); median duration of therapy was 7.8 months for first line and 5.0 months for second line. Across all lines of therapy, disease progression was the primary reason for treatment discontinuation (>68% of patients); treatment-related serious adverse events occurred in <3% of cases.

Real-world data indicate heterogeneous treatment patterns among patients with HER2-positive unresectable LA/MBC progressing on HER2-directed therapies, potentially reflecting the disparity in medical reimbursement access among the countries included in the study.

Source:

Lee S-C, Chung W-P, Ngan RK-C, et al. Real-world treatment patterns in patients with HER2+ unresectable or metastatic breast cancer: interim results from HER2 REAL Asia cohort. Abstract presented at: ASCO Annual Meeting, June 2-6, 2023; Chicago, IL. Abstract 1047.