Abstract PS10-01: 6-year absolute invasive disease-free survival (IDFS) benefit of adding adjuvant pertuzumab to trastuzumab and chemotherapy for patients with early HER2-positive breast cancer: A STEPP analysis of the APHINITY (BIG 4-11) trial

摘要: Background: The primary analysis of the randomized, double-blind, placebo-controlled APHINITY trial, published in 2017, including 4804 patients (pts) with HER2-positive, early breast cancer 45.4 months9 median follow-up, demonstrated that adjuvant pertuzumab (P) added to trastuzumab and chemotherapy, statistically significantly improved invasive disease-free survival (IDFS) compared placebo (Pla) chemotherapy overall for pts node-positive (N+) disease. In 2019, updated descriptive analyses IDFS 74.1 sustained benefit adding P both (HR, 0.76; 95% CI, 0.64-0.91), N+ disease 0.72; 0.59-0.87), while confidence intervals remained wide node-negative (N-) cohort 1.02; 0.69-1.53). There is great interest explore how these significant results translate into absolute treatment benefits different patient subpopulations. Methods: Subpopulation Treatment Effect Pattern Plot (STEPP) an exploratory, graphical method plots estimates effect overlapping subpopulations defined by a covariate interest. Four continuous covariates are considered defining this report: i) clinical composite risk score (see below), ii) TILs percentage, iii) HER2 FISH copy number, iv) clinical-biological combining previous three factors. Pts lowest values comprise extreme left STEPP subpopulation, highest right subpopulation. based on was calculated using Cox regression model following prespecified characteristics: number positive nodes, tumor size, age, centrally-reviewed hormone receptor status. Composite scores were scaled between 0 100 higher reflecting event. An example low factors would be T1N0 aged 40-64; high T3N2 or ages Results: Table 6-year percents (%) from Aphinity STEPPs, Overall N- cohorts. For each analysis, shown two at either (i.e. values) as well intermediate Conclusions: Based one table, subpopulation percentages had largest improvements Pla. Citation Format: Richard D. Gelber, Xin Victoria Wang, Bernard F. Cole, David Cameron, Fatima Cardoso, Vivianne Tjan-Heijnen, Ian Krop, Sherene Loi, Roberto Salgado, Astrid Kiermaier, Elizabeth Frank, Debora Fumagalli, Carmela Caballero, Evandro de Azambuja, Marion Procter, Emma Clark, Eleonora Restuccia, Sarah Heeson, Jose Bines, Sibylle Loibl, Martine Piccart-Gebhardt. HER2-positive cancer: A (BIG 4-11) trial [abstract]. In: Proceedings 2020 San Antonio Breast Cancer Virtual Symposium; Dec 8-11; Antonio, TX. Philadelphia (PA): AACR; Res 2021;81(4 Suppl):Abstract nr PS10-01.