FDA Grants Accelerated Approval to Atezolizumab Combination in Triple-Negative Breast Cancer
Posted: Monday, March 11, 2019
On March 8, 2019, the U.S. Food and Drug Administration (FDA) granted accelerated approval to atezolizumab (Tecentriq) plus nanoparticle albumin-bound (nab)-paclitaxel (Abraxane) in the treatment of adults with unresectable, locally advanced or metastatic, PD-L1–positive triple-negative breast cancer. PD-L1 status is determined by an FDA-approved test. This combination therapy is the first immunotherapy regimen to be approved in breast cancer. This accelerated approval is based on data from the phase III IMpassion130 study and is contingent on the results of a confirmatory trial.
In the IMpassion130 trial, atezolizumab plus nab-paclitaxel significantly reduced the risk of disease worsening or death by 40% compared with nab-paclitaxel alone (median progression-free survival = 7.4 vs. 4.8 months; hazard ratio = 0.60; 95% confidence interval = 0.48–0.77; P < .0001) in PD-L1–positive patients with unresectable locally advanced or metastatic triple-negative breast cancer who had not received prior chemotherapy for metastatic disease. Overall survival results were immature.
Safety in the atezolizumab plus nab-paclitaxel arm appeared consistent with the known safety profiles of the individual treatments, and no new safety signals were identified with the combination. The most common grade 3 to 4 side effects (≥ 2%) in both treatment arms were neutropenia, decreased neutrophil count, peripheral neuropathy, fatigue, and anemia.
The monoclonal antibody atezolizumab binds with PD-L1 expressed on tumor cells and tumor-infiltrating immune cells, blocking its interactions with both PD-1 and B7.1 receptors.