SABCS 2019 – TNBC: add-on atezolizumab fails to boost pathologic complete response


  • Emily Willingham, PhD
  • Univadis
Access to the full content of this site is available only to registered healthcare professionals. Access to the full content of this site is available only to registered healthcare professionals.

Takeaway

  • Atezolizumab added to neoadjuvant chemotherapy in patients with triple-negative breast cancer (TNBC) yielded no improvements in pathologic complete response (pCR).

Why this matters

  • This trial is part of the quest for interventions beyond chemotherapy for this aggressive disease with a high relapse probability.
  • The authors caution that longer term results may change conclusions and that the primary endpoint of the study is event-free survival, not pCR.

Key results

  • Clinical overall response rates were 76.1% (95% CI, 68.1%-82.9%) with atezolizumab vs 68.3% (60.0%-75.9%) without.
  • In the intention-to-treat analysis, pCR rates were:
    • 43.5% (95% CI, 35.1%-52.2%) with atezolizumab and 40.8% (32.7%-49.4%) without (OR, 1.11; P=.66).
  • In the safety data, abnormal liver enzymes stood out in the atezolizumab group.

Study design

  • Multicenter open-label trial with 280 participants with TNBC randomly allocated to neoadjuvant treatment with or without atezolizumab.
  • Primary outcome: event-free survival at 5 years.
  • Secondary outcome: pCR.
  • Funding: Hoffmann-La Roche, Ltd; Celgene International Sarl.

Limitations

  • Post-surgery effects of therapy not yet included.
  • Results presented at a conference without peer review.