The panel voted 10-1 in favor of the drug, which
would, if approved, be sold under the brand name Zontivity. The FDA
is not bound to follow the advice of its advisory panels but
typically does so.
Results from a trial known as TRA 2P were "robust," panelists said,
and justified approval for patients who had suffered a heart attack.
They agreed with the company that the drug should not be used in
patients with a history of stroke, since there was an increased risk
of bleeding in the brain in this group of patients.
"I think this drug addresses a real unmet medical need," said Dr.
Philip Sager, consulting professor of medicine at Stanford
University School of Medicine.
The vote followed a positive analysis by reviewers for the FDA,
whose report, published on Monday, also recommended the drug be
Vorapaxar works by preventing blood cells, or platelets, from
clumping together and forming clots in the arteries, which can lead
to heart attacks.
Other anti-platelets include aspirin and Plavix, which is made by
Bristol-Myers Squibb Co. Merck's drug works in a different way, by
inhibiting a receptor known as PAR-1.
The drug increased the overall risk of bleeding in clinical trials,
though the risk in patients who had not had a stroke did not
outweigh the drug's benefit, panelists said.
Still, Dr. Sanjay Kaul, a cardiologist and professor at UCLA School
of Medicine who voted in favor of approval, urged the FDA to "do its
due diligence" around the bleeding risk.
Each year about 190,000 Americans have a second heart-related event,
according to Merck. Standard therapy to prevent a second episode
often includes treatment with aspirin and Plavix. Vorapaxar would be
given in addition to standard treatment.
[to top of second column]
"The results of today's advisory committee mark an
important milestone in our effort to bring vorapaxar to appropriate
patients with a history of heart attack," Dr. Daniel Bloomfield, who
leads Merck's cardiovascular research, said in a statement. "We look
forward to working with the FDA as it completes its review."
Merck has proposed that the drug's label urge caution when
prescribing the drug for patients who weigh less than 60 kilograms
(132 lbs) since the risk of bleeding in these patients appears to be
higher than in heavier patients.
Panelists could not reach a consensus recommendation on how
lower-weight patients should be treated. Representatives from the
FDA said they will continue to discuss the matter before making
their final ruling.
(Reporting by Toni Clarke in Washington;
editing by Nick Zieminski and Dan Grebler)
[© 2014 Thomson Reuters. All rights
Copyright 2014 Reuters. All rights reserved. This material may not be published,
broadcast, rewritten or redistributed.