Abstract OT2-01-05: A prospective real-world national study to evaluate the efficacy and safety of adjuvant biosimilar trastuzumab in the treatment of HER2-positive breast cancer

Abstract

Background: Treatment with anti-HER2 therapy significantly improved survival outcomes in patients with HER2-positive Breast Cancer (BC). In Brazil, Trastuzumab was the first biosimilar approved in the treatment of patients with breast (any disease setting) and advanced gastric cancer with overexpression of HER2. Increase access to this important treatment may be enhanced with biosimilar approval. The aim of this Real-World study is to assess the efficacy and safety of adjuvant biosimilar trastuzumab in Brazilian patients with early HER2+ BC. Methods: This is a national, multicenter, observational prospective, real-world study in a variety of Brazilian institutions. A hundred and seventy adult patients, with diagnosis of early stage HER2-positive breast cancer, who received at least one dose of biosimilar trastuzumab (Zedora) as adjuvant therapy will be included. Patients will be followed for 5 years after the use of biosimilar trastuzumab (Zedora), unless recurrence or death. Safety outcomes will be recorded. Efficacy outcomes include invasive relapse-free survival (IRFS) rate at 18, 24, 30 and 36 months treatment initiation. Given the inexistence of a specific hypothesis to be tested, sample size was based on the accuracy of the two-sided 95% confidence interval (95% CI) for the invasive disease relapse-free survival rate. Results: In development countries such as as Brazil, oncology treatments with biological drugs have high costs and represent an import ibarrier to patients access to anti HER2 therapy. The use of biosimilars may result in significant health care savings. Conclusions: Considering the HERITAGE study, in which biosimilarity was clearly demonstrated between the reference monoclonal antibody and the biosimilar, we do expect to find the same safety and efficacy profile. Citation Format: Leandro Alves, Débora Gagliato, Mayara de Paula, Ana Carolina Cardoso, Alexandre Alcantara, Maristela Precivale, Vivienne Castilho. A prospective real-world national study to evaluate the efficacy and safety of adjuvant biosimilar trastuzumab in the treatment of HER2-positive breast cancer [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr OT2-01-05.

Real-World Clinical Outcomes of Biosimilar Trastuzumab (CT-P6) in HER2-Positive Early-Stage and Metastatic Breast Cancer

“…The same study reported better survival outcomes in patients with EBC or MBC who received treatment with RTZ, illustrating how the high cost of RTZ can deprive patients of effective treatments. As in previous studies (8,31,32), the results of this study also suggest that biosimilar trastuzumab may provide treatment as safe and effective as RTZ, but at a remarkably presented opportunity for cost-saving and thereby to improved access for patients of HER2 positive breast cancer.This real-world study suggests that the biosimilar CT-P6 has similar effectiveness and cardiac safety to RTZ in HER2-positive EBC and MBC, when administered as part of dual HER2-targetd therapy with pertuzumab and chemotherapy in the neoadjuvant or palliative first-line setting. CT-P6 was well tolerated, with a cardiac safety profile similar to that of the RTZ.…”

Evaluation of biosimilar trastuzumab MYL-1401O in HER2-positive early-stage and metastatic breast cancer in real-life data

“…A study conducted in China showed that the use of RTZ is higher in rich countries than in poor countries, and accordingly, survival is better in both the early and metastatic stages [28]. As in previous studies [1,11,26,29], our study has shown that biosimilar drugs are as effective and safe as RTZ. In this way, drug-expenditure will decrease and access to effective treatments will be easier.…”