The reviewers highlighted similar concerns on Jan. 15 ahead of a
scheduled meeting of an independent panel of experts advising the
FDA on the drug. However, the meeting was postponed due to a snow
FDA reviewers reiterated on Thursday their discomfort with trial
design, statistical analysis and overall effectiveness of the drug,
Sarepta is seeking accelerated approval for eteplirsen, which is
designed to treat a subset of patients with Duchenne muscular
dystrophy (DMD). There are no FDA-approved drugs for the disease and
most patients die by the age of 30.
After publication of the original review, Sarepta submitted
additional information and claimed "key inaccuracies" in the FDA
On Thursday, the reviewers not only disagreed with Sarepta's
rebuttal but said fresh information had cast further doubt on the
reliability of trial data.
Sarepta is conducting a "confirmatory" late-stage study, but it is
designed in a way that patients will either get eteplirsen or go
untreated. The reviewers said any potential beneficial effects of
the drug are unlikely to be large enough to detect unless the drug
is tested against a placebo in a large trial.
The reviewers didn't formulate a voting question for panelists to
ascertain whether they think Sarepta has provided enough evidence of
the drug's effectiveness to warrant approval.
"If there's no clear cut voting question then this is just a farce,"
said Janney Montgomery Scott analyst Debjit Chattopadhyay, who sees
a less-than 5 percent chance of approval.
Sarepta's shares fell as much as 47 percent to $10.50, wiping out
about $420 million of market value.
Pressure has been mounting on the FDA to approve treatments for the
progressive, muscle wasting disease.
The independent panel will discuss the drug on Monday. The FDA is
not obliged to follow its advice but usually does.
The head of the FDA's pharmaceuticals division, Dr. Janet Woodcock,
is expected to attend the meeting, indicating an unusually high
degree of scrutiny.
[to top of second column]
The agency has also set aside an exceptionally long period for
public commentary in the meeting, which will include testimony from
patients, family members and advocates.
"The panel will be tough ... although, no doubt parent/patient
testimony for 2.5 hours will pull on heartstrings," Wedbush
Securities analyst Heather Behanna said in an email.
Although most analysts see the staff assessment as the end of the
road for eteplirsen, the FDA has in the past brushed aside a
negative staff review in the face of strong advocacy.
Last year, the agency approved Addyi, the first drug to treat low
sexual desire in women, despite a scathing review from its staff.
Patient advocacy and clinician support could be an interesting
counterbalance at the eteplirsen meeting, as well as the expected
FDA decision date of May 26, William Blair's Tim Lugo said in a
The FDA staff's stern review of Sarepta's drug in January came a day
after the regulator rejected a rival drug developed by BioMarin
"BioMarin's drug is dead. Eteplirsen is now dead. There is nothing
in DMD for the foreseeable future," Chattopadhyay said.
(Reporting by Natalie Grover in Bengaluru; Editing by Maju Samuel
and Ted Kerr)
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