Rawson: Drug approval times [CMAJ

Drug approval times

CMAJ 2000;162(13):1804

In response to: J. Lexchin, B. Mintzes

Longer approval times in Canada cannot simply be attributed to fewer resources. Both the Swedish and UK drug regulatory agencies have similar resources to those of the Therapeutic Products Program yet consistently review and approve drugs in a similar timeframe to that of the United States. Although Australia has similar overall approval times to those in Canada, its scientific review is completed in significantly less time than Canada's [Research].¹

The Therapeutic Products Program's own performance standard and its actual performance on some drug submissions indicate that a full scientific evaluation can be completed in 6 months. The median time consumed by the safety and efficacy evaluation in a recent study of Therapeutic Products Program internal processes was 188 days (range 74–376 days).² Approval times are much longer for 2 reasons: considerable downtime occurs between the receipt of the application and the start of the scientific review, and the separate assessment of manufacturing and stability data is often not coordinated with the safety and efficacy evaluation.

An evaluation of the importance of a new drug's therapeutic potential should be based not simply on the lack of a current treatment, which is the practice of the Patented Medicine Prices Review Board, but rather it should be based on several factors. The US Food and Drug Administration (FDA) classifies all new drug applications to receive either a priority or a standard review based on the significance of the drug's "improvement" over currently marketed products. Improvement is shown by increased efficacy, elimination or substantial reduction of a treatment-limiting drug reaction, enhancement of patient compliance, or safety and efficacy in a new subpopulation. Of the 87 drugs approved in Canada, Australia, Sweden and the United States in 1992–1998, 37 (43%) received a priority review in the United States. Canadian approval times were significantly longer than those in Sweden and the United States both for drugs that received an FDA priority review and for those that did not.³ Thus, applications for all drugs, including those most likely to significantly affect the health of Canadians, are reviewed more expeditiously in Sweden and the United States than in Canada.

No one wants to trade more timely approvals for reduced safety. However, more concrete evidence about the safety of drugs given earlier approval than the reports cited by Joel Lexchin and Barbara Mintzes is available from an examination of drugs approved in the United States, but not in Canada, that were withdrawn for safety reasons. Between 1992 and 1998, there were only 4 such drugs.⁴ The approval times of these drugs ranged from 469 to 926 days; thus, their reviews were not rushed. Moreover, these 4 drugs constitute only 4.6% of drugs approved in the United States at least 1 year before approval in Canada in the 7-year period.

Finally, I endorse the recommendation that Canada's inadequate postmarketing surveillance system should be improved and have proposed new approaches that could be adopted in Canada.^5–7 However, the unnecessary delays in Canada's review and approval system should also be eliminated and Canada's performance standard of 355 days for all new drug applications achieved. In that way, Canadians will no longer have to experience delayed access to potentially valuable medicines.

Nigel S.B. Rawson
Division of Community Health
Faculty of Medicine
Memorial University of Newfoundland
St. John's, Nfld.

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References

Rawson NSB. Time required for approval of new drugs in Canada, Australia, Sweden, the United Kingdom and the United States in 1996–1998. CMAJ 2000;162(4):501-4. [MEDLINE]
Therapeutic Products Program: baseline assessment of drug submission review process. Ottawa: Price Waterhouse Coopers; 1999.
Rawson NSB, Kaitin KI. New drug approval times and "therapeutic potential" in Canada, Australia, Sweden and the United States in 1992-1998. Can J Clin Pharmacol. In press.
Woodcock J. The FDA maintains rigorous safety standards. Med Crossfire 1999;1:56-8.
Rawson NSB. An acute adverse drug reaction alerting scheme using the Saskatchewan Health datafiles. Drug Invest 1993;6:245-56.
Rawson NSB, Rawson MJ. Acute adverse event signalling scheme using the Saskatchewan administrative health care utilization datafiles: results for two benzodiazephines. Can J Clin Pharmacol 1999;6:159-66. [MEDLINE]
Rawson NSB, West R, Appel WC. Could "conditional release" of new drugs provide the information required to study drug effectiveness? — a discussion paper. Can J Clin Pharmacol. In press.