First Immunotherapy Combination Demonstrates Improved PFS in Triple-Negative Breast Cancer

Roche has announced that atezolizumab (Tecentriq), in combination with nab-paclitaxel (Abraxane), significantly reduced the risk of disease progression and mortality in patients with metastatic triple-negative breast cancer (TNBC). The announcement signifies the first phase 3 immunotherapy study to demonstrate statistically significant improvement in disease progression in TNBC, which represents 15% of breast cancer cases.

Results from the phase 3 IMpassion130 study showed that tecentriq plus chemotherapy, as first-line treatment, met its co-primary end point of progression-free survival (PFS). Roche noted that results were also encouraging for the study’s other primary end point, overall survival (OS), in the programmed death ligand-1 (PD-L1) positive population.

The study assessed the efficacy, safety, and pharmacokinetics of atezolizumab plus nab-paclitaxel compared with placebo plus nab-paclitaxel in 902 patients who had not previously received systemic therapy for metastatic breast cancer. PFS and OS were assessed in both the intention-to-treat population and those with PD-L1-positive tumors. Secondary end points included objective response rate, duration of response, and time to deterioration in Global Health Status/Health-Related Quality of Life.

The immunotherapy arm received 840 mg of atezolizumab intravenously on days 1 and 15 of each 28-day cycle and 100 mg of nab-paclitaxel on days 1, 8, and 15 of each 28-day cycle. The control arm received 100 mg of nab-paclitaxel on days 1, 8, and 15 of each 28-day cycle, in addition to placebo.

“IMpassion130 is the first positive phase 3 immunotherapy study in TNBC, and aggressive disease with limited treatment options,” said Sandra Horning, MD, chief medical officer and head of global development, Roche. “Highly encouraged by these results, we plan to submit to health authorities globally with the aim of bringing this combination to people with TNBC as soon as possible.”

Safety of atezolizumab plus nab-paclitaxel was consistent with the known safety profiles of each treatment, and no new safety signals were identified with the combination, according to Roche. They will continue follow-up of the study, along with 7 other ongoing phase 3 studies investigating atezolizumab in TNBC.

These results come just a week after Roche released positive data from its phase 3 IMpower133 study assessing the PD-L1 inhibitor plus chemotherapy as treatment for extensive-stage small cell lung cancer. The study of 403 patients demonstrated improved PFS and OS, meeting both of its co-primary end points.