Changes In Patient (Pt), Tumor, And Treatment Characteristics Over Time In 1st Line (1l) Trastuzumab (H) Plus Taxane (T; Paclitaxel/Docetaxel) Arms In Her2-Positive Metastatic Breast Cancer (Mbc) Trials.

e13024Background: A retrospective analysis showed improved progression-free survival and consistent underestimation of H+T efficacy assumptions in 1L HER2+ MBC trials over time (ISCB 2016). We evaluated changes in baseline/treatment characteristics and safety profile of H+T in 1L HER2+ MBC trials conducted 1995–2015. Methods: Trial-level data on pt/tumor/treatment characteristics and safety profile in H+T arms of 15 randomized trials were extracted from published data/clinical study reports. Characteristic/safety profile changes over time were explored by weighted regression; relevance was assessed by F-test. Results: Pt/tumor characteristics were generally stable over time. We observed relevant changes in types of adjuvant therapy used (Table). Serious adverse events (SAE) and study withdrawals due to AE decreased over time; rates of treatment discontinuation due to AE increased. Conclusions: In pts enrolled in 1L HER2+ MBC trials, use of adjuvant chemo-, hormonal, and radio-therapy decreased from 1995–2...