(Adds details, physician comment, background)
By Toni Clarke
Jan 15 Merck & Co Inc's experimental
blood clot-preventing drug vorapaxar should be approved to
reduce the risk of further heart problems in people who have
suffered a recent heart attack, an advisory panel to the U.S.
Food and Drug Administration concluded on Wednesday.
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
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
"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 approved.
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
"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
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)