A decision on whether to approve a controversial drug to combat Duchenne muscular dystrophy will not be made by Thursday, after all.
In a brief statement, Sarepta Therapeutics (SRPT) said Wednesday morning that the US Food and Drug Administration is continuing its review and will “work past” the May 26 deadline. This is the second time the agency has extended its time for deciding whether to approve the treatment and there is growing speculation the delay reflects political pressure on the FDA, as well as protracted debate among agency officials.
The debate over the Sarepta drug is one of the most closely watched FDA approval decisions in years because it is seen as a litmus test for the agency, which is grappling with increasingly assertive patient groups that want the FDA to take a more expansive view toward approving medicines for unmet medical needs.
The delay also comes as Dr. Robert Califf settles in to his new role as FDA commissioner and seeks to navigate mounting pressure from industry and some lawmakers to transform the agency process for approving new medical products.
It’s unclear when the agency will announce its decision. In premarket trading, Sarepta stock surged nearly 20 percent. On Tuesday, the shares rose on expectations the agency may approve the drug, despite a vote against recommending the medicine that was made by an FDA advisory panel last month.
One Wall Street analyst noted the delay appears to reflect political pressure, given that a growing number of lawmakers are urging the FDA to approve the drug. But he notes that the delay “extends the agony and the hope,” and cautiously suggested this may be a plus for the drug maker.
“Not only was the worst-case scenario averted, but this extension by FDA, which appears open-ended and not the standard three-month type, buys more time for the company’s supporters and the DMD patient community to exert additional pressure to FDA,” wrote RBC Capital Markets analyst Simos Simeonidis in an investor note. Nonetheless, based on the FDA staff analysis, he continues to believe the chances of approval are “limited.”
FDA staff have questioned whether the drug can produce sufficient levels of a protein called dystrophin. Without this protein, muscle fibers degenerate and voluntary movement becomes impossible. Agency staff also have doubts about the validity of a 12-patient study, which was not run according to the usual standards, and the viability of six-minute walking tests that trial participants underwent.
“We have a hard time imagining the agency setting the precedent of approving a drug with such a limited dataset,” Simeonidis added. “On the other hand, we cannot overlook the tremendous pressure being put on the FDA, and it is very difficult to gauge what may happen behind the scenes at the agency at the last minute.”
Another Wall Street analyst, however, believes the delay suggests the FDA will grant accelerated approval to endorse the Sarepta drug known as eteplirsen. This approach relies on a substitute outcome in a clinical trial to suggest a drug may have, but does not guarantee, a benefit.
“We think this delay incrementally increases the probability of accelerated approval but more meaningfully decreases the likelihood of a (rejection) that requires a randomized, placebo controlled study of eteplirsen,” wrote RW Baird analyst Brian Skorney in an investor note Wednesday
“The FDA has continued to put itself in a politically unfavorable position, should it present an uncompromised rejection, going into a year where PDUFA VI will be sculpted,” he added. He was referring to the sixth iteration of the Prescription Drug User Fee Act, which Congress must authorize for the agency to be paid industry fees.
One advocacy group reiterated the sense of urgency among parents.
“While we can certainly wait for the FDA’s decision, we cannot afford to lose another generation of boys to Duchenne because there weren’t treatment options. It is urgent that we get the right combination of approved treatments for our boys,” said Debra Miller, who heads CureDuchenne, an advocacy group that raises money to invest in drug makers that are developing products to combat DMD.