Canadian status of “not acceptable” drugs as evaluated by Prescrire: A cohort study

by Joel Lexchin

The independent French drug bulletin Prescrire International rates the therapeutic innovation of new drug-indications approved for marketing in France using an ordinal scale with the lowest rating being “not acceptable”. This study investigates whether these drugs were approved by Health Canada.

A list of “not acceptable” drug-indications was generated by handsearching all issues of Prescrire International between January 2013 and December 2022. The generic names, indications and reasons why Prescrire labeled them not acceptable were recorded. The approval date was determined by consulting the website of the European Medicines Agency (EMA). The status of these drug-indications in Canada was determined by searching multiple Health Canada websites. Therapeutic Evaluations for new drug-indications done by the Patented Medicine Prices Review Board (PMPRB) were recorded.

Prescrire rated 57 new drug-indications and 42 new indications for existing drugs as not acceptable. Seventy of these drug-indications were available in Canada– 42 new drug-indications and 28 new indications for existing drugs. Twenty (90.9%) of the 22 new drugs evaluated by the PMPRB were rated as slight/no therapeutic improvement and 2 as moderate therapeutic improvement. The median difference, in days, between approval times by the EMA/ANSM and Health Canada was 129 (interquartile range -102, 341) in favour of the former.

The majority of the not acceptable drug-indications were approved by Health Canada. The difference between when Prescrire and Health Canada examined the evidence for these drug-indications is unlikely to explain the difference in their evaluations. A change in regulatory standards at Health Canada may be one factor behind the presence of these drugs. To what degree those drugs led to more harms than benefits for patients who are taking them needs to be urgently investigated. Finally, the reasoning behind Health Canada’s approval of these drugs should be interrogated.