Since the US Food and Drug Administration (FDA) introduced its ‘accelerated approval pathway’ for drugs, in 1992, nearly half of the 253 drugs authorised by this process have not been confirmed as clinically effective, found an exclusive investigation by The BMJ.
Carrying out analysis of FDA data to year-end 2020, The BMJ found that of the 112 drugs, approved in the last 28 years, more than one fifth had been on the market for at least five years, and some had received approval more than two decades ago.
The accelerated pathway allows drugs to be approved for use once safety data, but before efficacy, has been proven. However, as part of the process, manufacturers should conduct post-approval studies – Phase IV Confirmatory Trials – to verify the anticipated clinical benefit. If a trial shows no benefit, the FDA can cancel a drug’s approval.
But further analysis of FDA data revealed that only 16 drugs approved under the accelerated pathway have been withdrawn. Most of these were shown to lack efficacy, but in some cases the confirmatory trials were never conducted.
The BMJ asked the manufacturers of 24 treatments that have been on the market for more than five years whether they had conducted phase IV trials. Six drugs had been withdrawn, approved, or postponed. But out of the remaining 18 drugs, just one third of manufacturers provided information on a relevant trial. And, of these, only four had started to recruit patients, while two companies said they were still discussing study design with the FDA.
Despite the pathway’s intended purpose of accelerating the availability of drugs that treat serious diseases, experts are concerned that the process is now being exploited by firms – to the potential detriment of patients, who may be prescribed a drug that offers little benefit.
Huseyin Naci, associate professor of health policy at the London School of Economics, said: “We may have drugs on the market that don’t have any benefits, but certainly predictably have harms associated with them.”
Rachel Sachs, an associate professor of law at Washington University, said: “There are some instances where the companies really do seem to be taking advantage of the accelerated approval pathway and are using it in a way that makes it harder to get at the truth about whether these products really are effective.”
An FDA spokesperson said: “[The FDA is] committed to working with sponsors to ensure that confirmatory studies are completed in a timely manner. We expect sponsors to commit all resources needed to move trials forward as effectively as possible, with the aim of completing trials as soon as is feasible, while assuring the quality of the data and the robustness of the results.”
To read the full report: https://www.bmj.com/content/374/bmj.n1898