* Agency cites concerns with niacin added to pain drug
* FDA advisory panel to give input on Thursday
* Acura shares fall 21 percent
(Adds company comment, updates share price)
By Lisa Richwine
WASHINGTON, April 20 U.S. regulators questioned
if an experimental pain drug from King Pharmaceuticals KG.N
and Acura Pharmaceuticals (ACUR.O) would deter abuse, documents
released on Tuesday showed.
Shares of Acura, which is aiming to win approval for its
first product, fell 21 percent to $6.23 on Nasdaq.
Acurox pairs an immediate-release form of the opioid
painkiller oxycodone with niacin, a B vitamin. Adding niacin
was meant to discourage people from taking multiple pills at
once as high niacin doses can cause uncomfortable flushing.
Food and Drug Administration staff, in a summary prepared
for an advisory panel, said "while the oxycodone component in
Acurox is efficacious, the agency has concerns about the use of
An Acura study suggested "niacin offers little in the way
of deterrence to oral abuse," the summary said. Studies showed
niacin's negative effects could be reduced by taking it with
Adding niacin also "appears to negatively affect the
adverse event profile of this drug," the FDA staff said, noting
higher reports of flushing in pain patients treated in Acurox
compared with a placebo.
The FDA will ask an advisory panel for input on the drug at
a public meeting on Thursday.
A key question will be if flushing is an acceptable risk
for legitimate patients with pain, according to a separate memo
prepared for the panel.
The agency also will ask the committee of outside experts
about the ability of food and over-the-counter pain medicines
to reduce flushing.
"These are clearly difficult questions for which there are
no easy answers," wrote Dr. Bob Rappaport, director of the FDA
division that is reviewing Acurox.
Acura, in a separate summary prepared for the panel, said
the drug would limit misuse without "without incurring an
incremental safety penalty." In addition to niacin, the drug
includes ingredients designed to cause burning in the nose if
an abuser crushes and snorts it. The drug also turns to a gel
if added to water or another solvent to discourage injection.
"It is not a perfect solution to the opioid abuse crisis,
but it is a solution that warrants approval of the product,"
the company said in the summary.
Acura Chief Financial Officer Peter Clemens said in an
interview that some patients in the company's late-stage
studies of Acura felt minor effects of niacin. But he said none
of the effects were severe or caused patients to drop out of
The FDA usually follows panel recommendations when deciding
whether to clear new products for sale.
King shares gained 8 cents to close at $11.50 on the New
York Stock Exchange.
(Reporting by Lisa Richwine, editing by Gerald E. McCormick)