Abstract
PURPOSE: The prevalence of off-label anticancer drug use is not well characterized. The extent of off-label use is a policy concern because the clinical benefits of such use to patients may not outweigh costs or adverse health outcomes. METHODS: Prescribing data from IntrinsiQ Intellidose data systems, a pharmacy software provider maintaining a population-based cohort database of medical oncologists, was analyzed. Use of the most commonly prescribed anticancer drugs ("chemotherapies") that were patent protected and administered intravenously to patients in 2010 was examined. Use was classified as "on-label" if the cancer site, stage, and therapy line met the US Food and Drug Administration (FDA)-approved indication. All other use was "off-label." Off-label use was divided by whether it conformed to National Comprehensive Care Network (NCCN) Compendium recommendations, a basis of insurer coverage policies. IMS Health National Sales Perspectives was used to estimate national spending by use category. RESULTS: Ten chemotherapies met inclusion criteria. On-label use amounted to 70%, and off-label use amounted to 30%. Fourteen percent of use conformed to an NCCN-supported off-label indication, and 10% of off-label use was associated with an FDA-approved cancer site, but an NCCN-unsupported cancer stage and/or line of therapy. Total national spending on these chemotherapies amounted to $12 billion (B; $7.3B on-label, $2B off-label and NCCN supported; $2.5B off-label and NCCN unsupported). CONCLUSION: Commonly used, novel chemotherapies are more often used on-label than off-label in contemporary practice. Off-label use is composed of a roughly equal mix of chemotherapy applied in clinical settings supported by the NCCN and those that are not.