Triple-negative breast cancer (TNBC) is an aggressive subtype with a high incidence in young patients, and it is associated with a high risk of disease progression. Until recently, one strategy for treating early stage TNBC was chemotherapy after surgery. Nowadays, the standard of care for patients with stage II-III TNBC includes neoadjuvant chemotherapy plus pembrolizumab, followed by surgery and locoregional radiotherapy if indicated, and adjuvant pembrolizumab.1 The ALEXANDRA/Impassion030 trial investigated whether adding 1 year of atezolizumab to postoperative chemotherapy could improve outcomes in patients with high-risk, stage II or III TNBC.2
This international, open-label, phase III trial randomised 2,199 patients with stage II or III TNBC who had undergone definitive surgery to receive either standard postoperative chemotherapy for twenty weeks with up to one year of atezolizumab (N= 1,101) or chemotherapy alone (N= 1,098). The primary endpoint was invasive disease-free survival (IDFS), defined as the time between randomisation and invasive breast cancer in the same or opposite breast, recurrence elsewhere in the body, or death from any cause.
Patient enrolment was halted by the study independent data monitoring committee and all patients stopped atezolizumab following a planned early interim and futility analysis. The trial continued to a premature final analysis. After a median follow-up of 32 months, the addition of atezolizumab did not improve outcomes. IDFS events occurred in 12.8% of patients receiving atezolizumab and chemotherapy compared to 11.4% in the chemotherapy-only group (HR[95% CI]: 1.11[0.87-1.42], p= 0.38). While the incidence of grade 3 or 4 treatment-related adverse events was higher in the atezolizumab group (54% vs 44%), fatal adverse events (0.8% vs 0.6%) and adverse events leading to chemotherapy discontinuation rates were similar between the two arms.
The addition of atezolizumab to postoperative chemotherapy did not demonstrate a benefit in reducing recurrence or death in high-risk early stage TNBC patients.
Top
