Some US drugs with “accelerated approval” lack strong clinical evidence
Some drugs that have been given “accelerated approval” by the US Food and Drug Administration (FDDA) to be made available to the American public lack stringent clinical evidence proving their benefits, according to a new study published by researchers from US and the London School of Economics and Political Science (LSE) in the UK.
Between 2000 and 2013, the study assessed 37 new drugs given accelerated approval by the FDA.
Drugs eligible for accelerated approval are assessed as “reasonably likely” to provide clinical benefits but the bar for their market entry is far lower than those receiving regular approval, according to Dr. Huseyin Naci, an LSE health policy researcher.
Dr. Naci said: “FDA’s accelerated approval pathway allows potentially promising drugs to receive marketing authorization on the basis of surrogate measures that are easy to obtain, rather than clinically meaningful outcomes. The evidence ultimately accrued on these drugs has major flaws and is inadequate to address the information needs of patients and doctors.”
The study is the first in the world to systematically evaluate more than 7000 clinical studies conducted on drugs receiving accelerated approval by the FDA.
Dr. Naci said the shortcomings were as a result of the FDA introducing more flexibility to its evidence standards over the past three decades.
According to the key findings reported by Dr. Naci and his colleagues from the University of Pennsylvania and Stanford University in the US, randomized trials – which are the gold standard of evaluating clinical effectiveness – accounted for only a small minority of existing evidence. One-third of randomized trials were in therapeutic areas outside of FDA approval and less than half evaluated the therapeutic benefit of the drugs, but used them instead as common backbone treatments.
They also found the drugs receiving accelerated approval were often tested concurrently in different therapeutic areas. For most drugs, no substantial time lag was apparent between the average start date of trials evaluating their effectiveness and their use as background therapy.
