The FDA granted accelerated approval to atezolizumab plus chemotherapy for the treatment of adults with PD-L1-positive, unresectable, locally advanced or metastatic triple-negative breast cancer, according to a press release from the manufacturer.
The approval of atezolizumab (Tecentriq, Genentech) plus nab-paclitaxel (Abraxane, Celgene) is based on PFS data from the ongoing randomized, phase 3 IMpassion130 study; ongoing approval may depend upon substantiation and description of clinical benefit in confirmatory trials.
“The FDA approval of this Tecentriq combination is an important treatment advance for people with PD-L1-positive, metastatic triple-negative breast cancer, a disease with high unmet medical need,” Sandra Horning, MD, chief medical officer and head of global product development at Genentech, said in a press release. “This Tecentriq combination is the first cancer immunotherapy regimen to be approved in breast cancer, representing a meaningful step forward in the understanding of this disease.”
The approval applies to patients whose tumors express PD-L1 in an FDA-approved test.
Atezolizumab is a monoclonal antibody designed to bind with PD-L1 expressed on tumor cells and tumor-infiltrating immune cells, inhibiting its interactions with both PD-1 and B7.1 receptors.
The multicenter, double-blind IMpassion130 study is evaluating the safety and efficacy of atezolizumab and nab-paclitaxel vs. placebo and nab-paclitaxel among 902 patients with unresectable, locally advanced or metastatic triple-negative breast cancer who had no previous systemic therapy for metastatic disease. PFS among the intention-to-treat population and patients with PD-L1-positive disease and OS in the intention-to-treat population served as the co-primary endpoints.
Results showed significantly longer median PFS with the atezolizumab regimen vs. nab-paclitaxel alone (7.4 months vs. 4.8 months; HR = 0.6, 95% CI, 0.48-0.77).
Data on OS were immature, with 43% of events in the entire intention-to-treat population. Further data will be reported to the FDA and presented at a future medical meeting.
The atezolizumab plus nab-paclitaxel group demonstrated a safety profile consistent with the known safety of each drug, and the combination yielded no new safety signals.
The most common grade 3 to grade4 adverse events among 2% or more of patients included low white blood cells, tingling or numbness in the hands and feet, reduced neutrophil count, fatigue, low red blood cells, low blood potassium level, pneumonia and increased blood level of aspartate transaminase.
The most common adverse events among 20% or more of patients were hair loss, fatigue, numbness in the hands and feet, nausea, diarrhea, low red blood cells, constipation, cough, headache, low white blood cells, diminished appetite and vomiting.
“The Tecentriq regimen is an exciting new treatment option for certain people living with metastatic, triple-negative breast cancer, a difficult-to-treat form of the disease,” Hayley Dinerman, executive director of the Triple Negative Breast Cancer Foundation, said in the release. “Chemotherapy alone has been the mainstay of treatment for many years, so it’s encouraging to now have an immunotherapy combination available for people with PD-L1 positive disease.”