Questions about the evidence behind the approval of the rare-disease drug Tavneos have raised concerns about post-marketing oversight, the FDA’s approval standards, and the integrity of the clinical-trial system. Some experts argue that the drug should no longer remain on the market, while Amgen and regulators continue to dispute whether available evidence supports continued approval in the European Union, the United Kingdom, and elsewhere.
Experts question the evidence for Tavneos
Under the law, Tavneos “really shouldn’t remain on the market,” said Joshua Skydel, a clinical fellow in rheumatology at Yale-New Haven Hospital and a fellow at the Yale Collaboration for Regulatory Stringency, Integrity, and Transparency.
The FDA’s drug-approval standards require substantial evidence of safety and effectiveness. Skydel said the case raises questions about key clinical trials, noting that some studies cited by Amgen have not yet been published. “I would like them to at least go through peer review before I hang my hat on them,” he said.
Hogue, however, is skeptical that clinical evidence gathered since Tavneos was approved will do much to support the company’s claims. “We suspect that the real-world data that was already available at the time we requested the retraction in April would not meet the FDA’s standard of evidence for approval,” she wrote. “We know there is insufficient data to support continued marketing approval” in the EU and the UK.
Unfinished post-marketing studies
Skydel also noted that the FDA requested additional post-marketing studies when Tavneos was approved, but Amgen has missed deadlines for completing them.
“For me, this episode really highlighted the way drugs reach the market with unanswered questions,” Skydel said. “Our ability to answer these questions is really only as strong as the collaboration between FDA and industry.” He also noted the FDA’s willingness to exercise its authority after a drug reaches the market.
FDA warns of broader consequences
In an April letter, the FDA argued that the stakes extend beyond patients with a single rare disease. Discontinuing the drug is “critically important to protect public health and the integrity of the drug approval process,” the agency said.
Without consequences, the FDA added, other companies would have an incentive to engage in deceptive practices.
Walter Craft, who voted to recommend Tavneos for approval based on the information available at the time, is also concerned about possible spillover effects. The clinical-trial system “is built on a level of trust,” he said. “And when that trust is called into question because of narrow parochial interests, it puts the entire system at risk for other subsequent actors in that space.”
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Source: arstechnica.com