Objectives: To systematically assess clinical and economic evidence for oncology orphan drugs marketed in the United States and to highlight the challenges and opportunities for evidence development within this pharmaceutical category.
Study design: Systematic review.
Methods: We conducted systematic literature searches of the Medline and Embase databases for clinical and cost-effectiveness studies published before June 2010 for all oncology orphan drugs marketed in the United States. We used the Grading of Recommendations Assessment, Development and Evaluation method and the Quality of Health Economic Studies criteria to assess the quality of the selected studies.
Results: We identified 60 randomized controlled trials and 21 cost-effectiveness analyses to support 47 oncology orphan drugs. A total of 21 drugs had moderate or high-quality bodies of clinical evidence, 11 had low-quality or very low quality clinical evidence, and 15 drugs could not be evaluated because we were unable to identify clinical evidence that met our inclusion criteria. The Spearman rank correlation coefficient for the level of evidence for oncology orphan drugs and disease prevalence was 0.3 (95% confidence interval, 0.0-0.5). The cost-effectiveness analyses received quality scores between 72 and 100 (range 0-100), with a mean score of 85.
Conclusions: The results of our study show that oncology orphan drugs marketed in the United States have varying levels and quality of clinical evidence and a paucity of evidence regarding economic value. Innovative analytic and policy approaches are needed to develop and implement a decision-making framework for this pharmaceutical category that is consistent with evidence-based medicine and comparative effectiveness research.