A Systematic Review and Meta-Analysis of Bevacizumab in First-Line Metastatic Breast Cancer: Lessons for Research and Regulatory Enterprises

J Natl Cancer Inst. 2020 Apr 1;112(4):335-342. doi: 10.1093/jnci/djz211.


Background: The US Food and Drug Administration's accelerated approval and later withdrawal of bevacizumab in patients with metastatic breast cancer (mBC) is a seminal case for ongoing debates about the validity of using progression-free survival (PFS) as a surrogate measure for overall survival (OS) in cancer drug approvals. We systematically reviewed and meta-analyzed the evidence around bevacizumab's regulatory approval and withdrawal in mBC.

Methods: We searched for all published phase II or III clinical trials testing bevacizumab as a first-line therapy for patients with mBC. Data were extracted on trial demographics, interventions, and outcomes. Descriptive analysis was stratified by whether the trial was initiated before, during, or after the accelerated approval. We used a cumulative random-effects meta-analysis to assess the evolution of evidence of the effect of bevacizumab on PFS and OS. We estimated the association between the trial-level PFS and OS effect using a nonlinear mixed-regression model.

Results: Fifty-two studies were included. Trial activity dramatically dropped after the accelerated approval was withdrawn. Eight clinical trials reported hazard ratios (hazard ratios) and were meta-analyzed. The cumulative hazard ratio for PFS was 0.72 (95% CI = 0.65 to 0.79), and the cumulative hazard ratio for OS was 0.90 (95% CI = 0.80 to 1.01). The regression model showed a statistically nonsignificant association between PFS benefit and OS benefit (β = 0.43, SE = 0.81).

Conclusion: The US Food and Drug Administration's decision-making in this case was consistent with the evolving state of evidence. However, the fact that seven clinical trials are insufficient to conclude validity (or lack thereof) for a trial-level surrogate suggests that it would be more efficient to conduct trials using the more clinically meaningful endpoints.

Publication types

  • Meta-Analysis
  • Research Support, Non-U.S. Gov't
  • Systematic Review

MeSH terms

  • Antineoplastic Agents, Immunological / therapeutic use
  • Bevacizumab / therapeutic use*
  • Breast Neoplasms / drug therapy*
  • Breast Neoplasms / pathology
  • Clinical Trials, Phase II as Topic / methods
  • Clinical Trials, Phase II as Topic / statistics & numerical data
  • Clinical Trials, Phase III as Topic / methods
  • Clinical Trials, Phase III as Topic / statistics & numerical data
  • Decision Making
  • Drug Approval / methods*
  • Endpoint Determination
  • Female
  • Humans
  • Legislation, Drug
  • Neoplasm Metastasis
  • Nonlinear Dynamics
  • Progression-Free Survival
  • Randomized Controlled Trials as Topic / methods
  • Randomized Controlled Trials as Topic / statistics & numerical data
  • Regression Analysis
  • Survival Rate
  • United States
  • United States Food and Drug Administration


  • Antineoplastic Agents, Immunological
  • Bevacizumab