Gap between the US and Japan in coverage of pharmacogenomic biomarkers by health insurance programs: More coverage is needed in Japan.

In this study, we aimed to understand the gap in coverage of pharmacogenomic (PGx) biomarkers between Japan and the US. PGx biomarkers (1) in the Clinical Pharmacogenetics Implementation Consortium (CPIC) guidelines; (2) that are CPIC level A or B; or (3) have US Food and Drug Administration (FDA)-approved drug labels, were determined. Subsequently, their coverage by US health insurance companies and the National Health Insurance (NHI) in Japan was investigated. We identified the top six health insurance companies with the largest market shares in the US and investigated the coverage for the PGx biomarkers by these health insurers, Medicare, Medicaid, and the NHI in Japan. We found that 19.9% of these biomarkers are covered by the six companies (10.0%, the CPIC guidelines; 25.1%, the FDA-approved drug labels). The coverage of somatic and germline biomarkers was respectively 86.8% and 8.5% in the US and 56.3% and 0.6% in Japan. A few germline PGx biomarkers are covered both in Japan and the US, but the coverage of both somatic and germline biomarkers was lower in Japan. Therefore, more coverage should be considered to improve patient outcomes after prescribing medications in Japan.