Merck Drug May Have Fewer Side Effects Than Paxil (Update1)
Bloomberg News
September 10, 1998, 4:26 p.m. ET
Merck Drug May Have Fewer Side Effects Than Paxil (Update1)
(Adds background in 3rd paragraph, analyst comment in 4th.)
Washington, Sept. 10 (Bloomberg) -- Merck & Co., the world's
biggest drugmaker, said an early study indicates an experimental
depression drug may have fewer side effects than one of the top
sellers currently available, SmithKline Beecham Plc's Paxil.
In a six-week study of about 210 patients, Merck's new drug
produced less sexual dysfunction, ejaculation disorders and
impotence than did SmithKline's Paxil. Merck's drug also seemed
to treat depression at least as well.
Merck needs to develop new drugs to make up for the expected
loss of patents by 2001 on four medicines that had more than $5
billion in 1997 sales. So far, the data on Merck's new drug makes
it seem unlikely that it could soon replace blockbuster such as
the high-blood pressure medicine Vasotec.
''It's a little bit short of the home run that Merck
needs,'' said James Keeney, an analyst with ABN Amro, who has a
''hold'' on Merck. ''There's a lot more work to do here.''
Merck is trying to treat depression in a new way. Its drug
appears to interfere with different naturally occurring brain
chemicals than do existing antidepressants such as Paxil, Eli
Lilly & Co.'s Prozac and Pfizer Inc.'s Zoloft. Merck's drug
targets a compound, substance P or NK1, first identified in 1931,
while its role in depression is a new discovery.
''The pharmaceutical industry must be commended for its
persistence,'' said Claes Wahlestedt of the Center for Genomic
Research in an essay that accompanies the study published in
tomorrow's edition of Science magazine.
Merck, based in Whitehouse Station, New Jersey, fell 2 5/8
to 123 13/16. Merck still is testing its new drug, trying to
enter one of the biggest drug markets. Three of the world's 10
best-selling drugs in 1997 were antidepressants, according to
Hambrecht & Quist.
Mood Disorders
Mood disorders such as depression affect 18 million adults
in the U.S., according to the National Institute for Mental
Health. The top-selling antidepressant, Lilly's Prozac, had sales
of $2.56 billion in 1997. Sales of the 10-year-old drug rose 11
percent in the first half of 1998 as Lilly targeted consumers
directly with ads in popular magazines. Paxil and Zoloft each had
1997 sales of $1.5 billion.
The three drugs work on the brain chemical serotonin, which
is linked to regulating mood and appetite. Merck's drug, called
MK-869, targets substance P. The chemical had long been thought
to be linked to pain.
Merck tested the drug in about 210 patients, dividing the
group into three. Patients in one group received a large dose of
MK-869, 300 milligrams a day. Another group took 20 milligrams of
Paxil and the other was given a placebo.
In the Paxil group, 26 percent of patients reported sexual
dysfunction, compared with 3 percent of those on the Merck drug
and 4 percent on placebo.
The Paxil group also had higher reports of impotence, 10
percent, compared with 3 percent for the Merck group and 4
percent for placebo.
More patients on the Merck drug, 32 percent, reported
headaches than those on Paxil, 28 percent, and placebo, 24
percent.
In this test, patients were randomly assigned to the three
groups. Neither they nor the researchers knew until the end of
the test who received Paxil, the Merck drug or the placebo.
Researchers commonly test drugs this way to try to weed out the
influence of patients' perceptions of a drug.
--Kerry Dooley in the Princeton newsroom (609) 279-4016/dd |
