First Cancer Immunotherapy Regimen Approved for Breast Cancer

The FDA has granted accelerated approval to the combination regimen of atezolizumab (Tecentriq, Genentech) and chemotherapy (Abraxane [paclitaxel protein-bound particles for injectable suspension (albumin-bound); nab-paclitaxel]) as a treatment for adults with unresectable locally advanced or metastatic triple-negative breast cancer (TNBC), whose tumors express PD-L1, as determined by an FDA-approved test.

With this approval, atezolizumab plus nab-paclitaxel is the first cancer immunotherapy regimen to be approved for breast cancer.

“The atezolizumab 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 a statement. “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.”

According to the press release, this accelerated approval is based on data from the randomized, double-blind phase 3 IMpassion130 study, which demonstrated that atezolizumab with nab-paclitaxel significantly reduced the risk of disease worsening or death (PFS) by 40% compared with nab-paclitaxel alone (median PFS=7.4 vs. 4.8 months; HR=0.60, 95% CI: 0.48-0.77, p<0.0001) in PD-L1-positive patients with unresectable locally advanced or metastatic TNBC who had not received prior chemotherapy for metastatic disease. Overall survival (OS) results were immature with 43% of events in all randomized patients (intent-to-treat; ITT), and further data will be shared with the FDA and presented at an upcoming medical meeting, according to Genentech.

The safety of the combination was consistent with the known safety profiles of the individual medicines, and no new safety signals were identified. The most common grade 3-4 adverse effects (≥2%) with the combination were low white blood cells, tingling or numbness in the hands and feet, neutrophil count decreased, feeling tired, low red blood cells, low blood potassium level, pneumonia, and increased blood level of a liver enzyme (AST). The most common adverse effects (≥20%) were hair loss, feeling tired, tingling or numbness in the hands and feet, nausea, diarrhea, low red blood cells, constipation, cough, headache, low white blood cells, decreased appetite, and vomiting.

Continued approval for this indication may be contingent upon verification and description of clinical benefit in a confirmatory trial(s).

Reference

FDA Grants Genentech's Tecentriq in Combination With Abraxane Accelerated Approval for People With PD-L1-Positive, Metastatic Triple-Negative Breast Cancer [news release]. Genentech. https://www.gene.com/media/press-releases/14782/2019-03-08/fda-grants-genentechs-tecentriq-in-combi. Accessed March 8, 2019.