The 46 medicines that received approval through 2017 as part of the FDA's Breakthrough Therapy program are often sent to patients without sufficient evidence to back them or prove their benefits, a study published in JAMA found.
"Our research suggests that FDA approval of these breakthrough therapies is generally based on shorter and smaller clinical trials than those that support FDA approval of non-breakthrough therapy drugs," co-author Joseph Ross, MD, told Reuters.
The study did not look at whether the drugs were as effective and safe as preapproval testing suggested. The FDA does not always require such post-marketing studies for "breakthrough" drugs, Reuters reports.
The FDA's breakthrough program aims to speed up the approval process for medicines to treat life-threatening conditions in cases where tests suggest dramatic improvement compared to existing treatments.
"A lot of people, when they hear 'breakthrough designation,' assume the 'breakthrough' is based on great clinical trial evidence, but it's actually more of an expectation that this is promising," Dr. Ross told Reuters.
Four study findings, according to the research team's analysis of the 89 pivotal efficacy trials in the breakthrough program:
1. The study found 41 percent of the drugs were approved without a gold-standard type of trial, where researchers randomly assign patients to receive the drug or a placebo.
2. Over half — 54 percent — of approvals were granted without any double-blind testing, which means researchers knew the treatment each patient was receiving.
3. Only 22 percent of pivotal trials measured actual improvement in patients' well-being. The rest of the trials relied on substitute indicators that frequently do not translate to significant improvement.
4. Less than half — 46 percent — of drugs received approval despite being studied without a comparison of how the drug recipients did versus how patients with a placebo or an established therapy did.