A Review of Trastuzumab Biosimilars in Early Breast Cancer and Real World Outcomes of Neoadjuvant MYL-1401O versus Reference Trastuzumab

Abstract

The reduced cost of trastuzumab biosimilars has led to increased adoption for HER2-positive breast cancer. This review of trastuzumab biosimilars encompasses this development and real world clinical data in early breast cancer. In addition, we present a retrospective study evaluating the total pathological complete response (tpCR) rates (lack of residual invasive cancer in resected breast tissue and axillary nodes), of MYL-1401O to reference trastuzumab (TRZ) in the neoadjuvant setting for HER2+ early breast cancer (EBC) in Alberta, Canada. Neoadjuvant patients with HER2+ EBC treated with TRZ from November 2018–October 2019 and MYL-1401O from December 2019–September 2020 were identified. Logistic regression was used to control for variables potentially associated with tpCR: trastuzumab product, age, pre-operative T- and N-stage, grade, hormone receptor (HR)-status, HER2-status, chemotherapy regimen, and chemotherapy completion. tpCR was 35.6% in the MYL-1401O group (n = 59) and 40.3% in the TRZ (n = 77) group, p = 0.598. After controlling for clinically relevant variables, there was no significant difference in the odds of achieving tpCR in patients treated with TRZ versus MYL-1401O (OR 1.1, 95% CI 0.5–2.4, p = 0.850). tpCR rates were similar for patients treated with MYL-1401O compared to trastuzumab in our real world study of HER2+ neoadjuvant EBC and comparable to pivotal phase 3 trials.

Clinical Benefit, Price, and Uptake for Cancer Biosimilars vs Reference Drugs in China

“…A study from a clinical setting showed that the ORR of bevacizumab biosimilars was also comparable to that of the reference drug in patients with NSCLC . No significant difference in safety outcomes was observed between bevacizumab biosimilars and reference groups (eTable 13 in Supplement 1).…”

“…Of the 1195 records sourced from the database and manually searched, 49 studies met the inclusion criteria, including 39 RCTs 32-70 and 10 cohort studies. [71][72][73][74][75][76][77][78][79][80]…”

“…eFigure 2 in Supplement 1 shows the process of study screening. Of the 1195 records sourced from the database and manually searched, 49 studies met the inclusion criteria, including 39 RCTs and 10 cohort studies …”

“…Table 1 and eTable 7 in Supplement 1 summarize the characteristics of the 10 cohort studies with a total of 1998 patients . Of the 10 cohort studies, 1 (10.0%) was of a bevacizumab biosimilar, 3 (30.0%) were of rituximab biosimilars, and 6 (60.0%) were of trastuzumab biosimilars . All cohort study designs were retrospective.…”

“…Of the RCTs, 32 (82.1%) were low risk, 5 (12.8%) were uncertain risk, and 2 (5.1%) were high risk . Of the cohort studies, 4 (40.0%) were high risk and 6 (60.0%) were low risk …”