How Do Payers Respond to Regulatory Actions? The Case of Bevacizumab

Two views of cancer medicines: Imagery versus evidence

Despite advertising imagery portraying cancer medicines as offering substantial improvement or cure, most patients can expect modest or no incremental benefit from most new treatments, according to pre-specified criteria. When improvements in overall survival are demonstrated, they average just 2.1 months. Despite limited benefits, drug prices have risen while median household incomes have remained largely unchanged, and these higher prices are poorly correlated with improved outcomes. Better alignment of perception with demonstrated drug benefit could be achieved by limitations on advertising and improved labeling or other disclosures. Reforms are also needed to remove financial incentives to prescribe costlier drugs.

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

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 Trial activity dramatically dropped after the accelerated approval was withdrawn.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.

Over-treatment in metastatic breast cancer

Metastatic breast cancer is an incurable disease and the main goals of treatment are prolongation of survival and preservation/improvement of quality of life. Thus the main philosophy of treatment should be to use the least toxic methods, as long as they provide sufficient disease control. In ER-positive tumours this can be in many cases achieved by endocrine therapy; in HER2-positive cancers efficacy of backbone therapy can be enhanced by an anti-HER2 agent. In patients requiring chemotherapy, consecutive single agent regimen provide disease control of a duration at least comparable to multidrug regimen, at a cost of significantly lower toxicity and are a preferred strategy in the majority of cases. Available data demonstrate, however, that aggressive chemotherapy is still overused in many metastatic breast cancer patients. The objective of this manuscript is to critically review available data on treatment choices and sequence in metastatic breast cancer across all breast cancer subtypes in relation to possible overtreatment, including therapies which are not recommended by current guidelines or not even approved. Our aim is to provide guidance on applying these data to clinical practice, but also to describe various, often non-scientific factors influencing therapeutic decisions in an aim to identify areas requiring educational and possibly political actions.