THURSDAY, March 28, 2024 (HealthDay News) -- Patients with triple-negative breast cancer do not benefit from the addition of atezolizumab to their postsurgery chemotherapy treatment, according to a study presented at the annual European Breast Cancer Conference, held from March 20 to 22 in Milan.
Heather McArthur, M.D., from the University of Texas Southwestern Medical Center in Dallas, and colleagues conducted a phase 3 trial that investigated the efficacy and safety of adjuvant atezolizumab (atezo) plus standard anthracycline/taxane chemothreapy (atezo + chemo) versus standard anthracycline/taxane chemotherapy (chemo alone) in stage II to III triple-negative breast cancer. The analysis included roughly 32 months of median follow-up and 266 invasive disease-free survival events (iDFS).
The researchers found no improvement in survival or recurrence-free survival for patients treated with atezolizumab versus those not treated with atezolizumab. Among the patients taking atezolizumab, 12.8 percent had a recurrence or died versus 11.4 percent not taking atezolizumab (hazard ratio [HR], 1.11; 95 percent confidence interval [CI], 0.87 to 1.42). Similar results were seen for iDFS in the PD-L1-positive subset (HR, 1.00; 95 percent CI, 0.73 to 1.35), iDFS in the node-positive subset (HR, 1.32; 95 percent CI, 0.97 to 1.80), and overall survival (HR, 1.23; 95 percent CI, 0.87 to 1.73). Incidence of grade ≥3 treatment-related adverse events occurred among 54.3 percent in the atezo + chemo arm versus 44.1 percent in the chemo-alone arm.
"The results of this final analysis are important because they show that including the immunotherapy drug atezolizumab alongside chemotherapy does not help when it’s given to patients following surgery," McArthur said in a statement. "By extension, this also highlights the importance of treating triple-negative breast cancer with chemotherapy and immunotherapy prior to surgery, as per the current standard of care."