Pharmacogenomic biomarkers: Interpretation of information included in United States and Japanese drug labels

Abstract

Many drug labels contain information on pharmacogenomic biomarkers (PGBMs), but the information is not necessarily actionable. Pharmacogenomics Knowledgebase (PharmGKB) aims to clarify the level of action for PGBMs (PGx levels) implied in each label as issued by the US Food and Drug Administration. We wished to evaluate the association between the PGx level for US and Japanese drug labels and the insurance coverage for PGBM testing or approval for in vitro diagnostics (IVDs) in each country. We investigated the information on PGBMs in US and Japanese drug labels with PGx levels, insurance coverage of PGBM tests and IVD approval in the US and Japan. We analysed the relationship of PGx levels with insurance coverage. A total of 243 labels were listed by PharmGKB, and 215 (88%) had PGx levels for US labels and 52 (21%) for Japanese labels. Of the 215 US labels, 54 were designated as "Testing Required" in PGx levels. PGx levels in US labels were strongly associated with coverage of PGBM testing. Tests in 52 (96%) of the 54 labels with Testing Required had insurance coverage, 2 (50%) of 4 in "Testing Recommended," 38 (38%) of 100 in "Actionable PGx," 11 (19%) of 57 in "Informative PGx" and 3 (11%) of 28 in "No Level." In Japanese labels, only 14 of 52 were listed as Testing Required, and all were covered by the National Health Insurance in Japan. The PGx level given in drug labels provides information on availability of PGBM testing. Higher PGx levels, based on better evidence of usefulness of PGBM testing, provide a route to broader test coverage.