Results of IMpassion130
Presenting the final OS analysis from IMpassion130, Dr. Emens noted that the study’s findings have led to recommendations for atezolizumab plus nab-paclitaxel as first-line treatment of PD-L1-positive TNBC in international guidelines.
The median OS in the ITT population was 18.7 months in the placebo arm and 21.0 months in the atezolizumab arm (stratified HR, 0.87, P = .077). The 3-year OS rates were 25% and 28%, respectively.
The median OS in the PD-L1-positive population was 17.9 months in the placebo arm and 25.4 months in the atezolizumab arm (HR, 0.67). The 3-year OS rates were 22% and 36%, respectively.
A P value is not available for the between-arm OS comparison in the PD-L1-positive population. OS was not formally tested in this group because the OS boundary for statistical significance was not crossed in the ITT population. However, Dr. Emens said there was a “clinically meaningful” OS benefit observed with atezolizumab in the PD-L1-positive patients.
Treatment withdrawals caused by adverse events were more common in the atezolizumab arm (19% vs. 8%). The most common of these was neuropathy, Dr. Emens said. However, she noted that atezolizumab-related adverse events were generally low grade and easily managed.
“These results support a positive benefit-risk profile for atezolizumab plus nab-paclitaxel as first-line therapy in patients with PD-L1-positive metastatic triple-negative breast cancer,” Dr. Emens concluded.
Both studies were funded by F. Hoffman–La Roche. Dr. Miles, Dr. Emens, and Dr. Carey disclosed financial relationships with Roche and other companies.
SOURCES: Miles D et al. ESMO 2020, Abstract LBA15; Emens LA et al. ESMO 2020, Abstract LBA16.