Between 1990 and 2003, the board appraised 1147 newly patented drugs (identified by active ingredient(s), formulation, and strength), including derivatives of existing medicines, such as esomeprazole. Of these new drugs, 68 (5.9%) met the regulatory criterion of being a breakthrough drug (“the first drug to treat effectively a particular illness or which provides a substantial improvement over existing drug products”).2
These included, for example, filgrastim, donepezil hydrochloride, and infliximab. We expanded the criterion for being a breakthrough drug, however, to include all subsequent formulations and dosages of a classified breakthrough drug, as well as all competing drugs to enter the chemical subgroup3
established by a classified breakthrough drug. All variants on a breakthrough drug were therefore also classified as breakthroughs. This increased the number of breakthrough products in our study to 142.
The remaining 1005 new drugs did not provide a “substantial improvement over existing drug products.” We classified them as “me-too” drugs. The Patented Medicine Prices Review Board's breakthrough assessments are not available for drugs first marketed before 1990; we therefore classified these only as “vintage brand” or “vintage generic” drugs. Generic versions of drugs marketed before 1990 were classified as vintage regardless of year of introduction.
From 1996 to 2003, per capita expenditure on prescription drugs in British Columbia more than doubled (from $141 (£78; €115) to $316) and per capita days of treatment supplied increased by just over half (from 194 to 301 days) (). Cost per day supplied rose from $0.73 to $1.05.
Figure 1 Use of prescription drugs and expenditure per capita, by product classification, British Columbia, Canada, 1996-2003. Data were extracted from BC PharmaNet, a computer network into which a record of all filled prescriptions (including the data field for (more ...)
Breakthrough drugs accounted for 6% of expenditure and 1% of use in 1996, and 10% of expenditure and 2% of use in 2003. Vintage brand and vintage generic drugs combined accounted for 75% of total use in 1996 and 54% in 2003, but only 53% and 27% of total annual expenditure for those two years respectively. In contrast, me-too drugs accounted for 44% of use and 63% of expenditure by 2003. Their average cost per day of treatment was twice that of vintage brand drugs and four times that of vintage generic drugs.