The Food and Drug Administration has granted accelerated approval for the combination of atezolizumab (Tecentriq) plus nanoparticle albumin–bound paclitaxel (nab-paclitaxel; Abraxane) for the treatment of adults with unresectable locally advanced or metastatic programmed death-ligand 1 (PD-L1)–positive triple-negative breast cancer (TNBC).
This conditional approval is granted to medicines that fill an unmet medical need for serious or life-threatening diseases or conditions, but the FDA may require confirmatory trials to provide verification and description of clinical benefit to allow continued approval.
The approval is based on the phase 3 IMpassion130 trial (NCT02425891), which enrolled 902 patients with unresectable, locally advanced or metastatic TNBC who had not received prior lines of chemo for metastatic disease, according to Genentech.
The multicenter, randomized, double-blind study has been evaluating the drug combination’s efficacy, safety, and pharmacokinetics. Compared with placebo plus nab-paclitaxel, atezolizumab/nab-paclitaxel demonstrated significantly superior progression-free survival (median PFS, 7.4 months vs. 4.8 months; hazard ratio, 0.60; 95% confidence interval, 0.48-0.77; P less than .0001).
The overall survival data for the intention-to-treat population remains immature, but further data will be shared with the FDA in the future, according to Genentech.
No new safety signals were seen in the atezolizumab/nab-paclitaxel arm, and the combination’s safety appeared consistent with the known safety profiles of each medicine individually.
The most common grade 3-4 events (occurring in more than 2% of patients) in the combination arm included low red blood cells, low white blood cells, feeling tired, low blood potassium level, and pneumonia.
The most common side effects (occurring in more than 20% of patients) in the combination arm included hair loss, tingling, nausea, diarrhea, headache, low red blood cells, low white blood cells, and decreased appetite.
Atezolizumab is a monoclonal antibody that binds to the PD-L1 receptor, which could possibly lead to the reactivation of T cells; however, atezolizumab also may interact with other cells in the body. Nab-paclitaxel is an injectable suspension of the common chemotherapy drug.
