JANUVIA(R), First in New Class of Oral Treatments Known as DPP-4 Inhibitors, Recommended for Approval for the Treatment of Type 2 Diabetes in the European Union

Editor's Note: For Use by Reporters in the European Union Only.

JANUVIA(R)(1) (sitagliptin), Merck, Sharp & Dohme's treatment for
patients with type 2 diabetes, today received a positive opinion from
the Committee for Medicinal Products for Human Use (CHMP) of the
European Medicines Evaluation Agency (EMEA) in Europe. The CHMP
opinion recommends that JANUVIA be approved in the European Union for
the treatment of type 2 diabetes. Following the conclusion of the CHMP
review, the opinion for JANUVIA will be transmitted to the European
Commission (EC). If the EC adopts the opinion, JANUVIA will be the
first and only prescription medication in a new class of drugs known
as dipeptidyl peptidase-4 (DPP-4) inhibitors, which enhance the body's
own ability to lower blood sugar (glucose) when it is elevated. The
decision will be applicable to the 27 countries that are members of
the European Union, including the United Kingdom, Germany, France,
Italy and Spain. JANUVIA is currently approved in eleven countries
including the United States and Mexico. Marketing authorization from
the European Commission is expected in early April after the adoption
of the opinion.

The CHMP, comprised of regulators from all European Union
countries, gave the positive opinion following a review of
comprehensive data supporting the efficacy and safety and tolerability
profile of JANUVIA. The submission package consisted of studies
involving approximately 4,000 patients with type 2 diabetes treated
with JANUVIA.

JANUVIA has been investigated in patients with type 2 diabetes to
improve glycaemic control in combination with metformin when diet and
exercise, plus metformin, do not provide adequate glycaemic control.
JANUVIA has also been studied as add on therapy with PPAR gamma
agonists in patients with type 2 diabetes mellitus in whom use of a
PPAR gamma agonist (e.g. a thiazolidinedione) is appropriate. In
addition, JANUVIA has been studied as monotherapy in many patients.

In a clinical study, JANUVIA plus metformin, compared to treatment
of a sulfonylurea (SU) plus metformin, showed comparable glucose
lowering efficacy. In this study patients taking JANUVIA plus
metformin lost weight (-1.5 kg) compared to patients taking glipizide
plus metformin who gained weight gain (+1.1 kg). Hypoglycaemia (when
blood sugar becomes too low) was more common in patients treated with
glipizide plus metformin (32 percent) compared to patients treated
with JANUVIA plus metformin (4.9 percent). In the overall phase III
clinical programme the incidence of hypoglycaemia in patients taking
JANUVIA was similar to patients taking placebo (1.2 percent, JANUVIA
vs. 0.9 percent, placebo). In clinical trials of up to 2 years in
duration, patients have received treatment with JANUVIA alone or in
combination with metformin, a sulfonylurea (with or without metformin)
or a PPAR gamma agent. In these trials, the rate of discontinuation
due to adverse experiences considered drug-related was 0.8 percent
with JANUVIA and 1.5 percent with other treatments. No adverse
reactions considered as drug-related were reported in patients treated
with JANUVIA occurring in excess (> 0.2 % and difference > 1 patient)
of that in patients treated with control. Reported adverse events
included nausea (common), somnolence, upper abdominal pain, diarrhoea
and hypoglycaemia (uncommon).** JANUVIA should not be used in patients
with type 1 diabetes or for the treatment of diabetic ketoacidosis, as
it would not be effective in these settings.

About JANUVIA

JANUVIA (sitagliptin) is an oral, once daily, potent and highly
selective DPP-4 inhibitor. DPP-4 inhibitors work by enhancing a
natural body process that lowers blood sugar, the incretin system.
When blood sugar is elevated, incretins work in two ways to help the
body regulate high blood sugar levels: they trigger the pancreas to
increase the release of insulin and signal the liver to reduce its
production of glucose. DPP-4 inhibitors enhance the body's own ability
to control blood sugar levels by increasing the active levels of these
incretin hormones in the body, helping to decrease blood sugar levels
in patients with type 2 diabetes.

Expanding Clinical Trial Program for JANUVIA

MSD's clinical development program for JANUVIA is robust and
continues to expand with 43 studies completed or under way, and four
more studies set to begin this year. There are about 6,700 patients in
the Company's clinical studies with about 4,700 of these patients
being treated with JANUVIA. Additionally, about 1,100 patients have
been treated with JANUVIA for more than a year.

About Merck

Merck & Co., Inc., which operates in many countries as MSD (Merck
Sharp & Dohme), is a global research-driven pharmaceutical company
dedicated to putting patients first. Established in 1891, Merck
currently discovers, develops, manufactures and markets vaccines and
medicines to address unmet medical needs. The Company devotes
extensive efforts to increase access to medicines through far-reaching
programs that not only donate Merck medicines but help deliver them to
the people who need them. Merck also publishes unbiased health
information as a not-for-profit service. For more information, visit
www.merck.com.

Forwarding-Looking Statement

This press release contains "forward-looking statements" as that
term is defined in the Private Securities Litigation Reform Act of
1995. These statements are based on management's current expectations
and involve risks and uncertainties, which may cause results to differ
materially from those set forth in the statements. The forward-looking
statements may include statements regarding product development,
product potential or financial performance. No forward-looking
statement can be guaranteed, and actual results may differ materially
from those projected. Merck undertakes no obligation to publicly
update any forward-looking statement, whether as a result of new
information, future events, or otherwise. Forward-looking statements
in this press release should be evaluated together with the many
uncertainties that affect Merck's business, particularly those
mentioned in the cautionary statements in Item 1 of Merck's Form 10-K
for the year ended Dec. 31, 2005, and in its periodic reports on Form
10-Q and Form 8-K, which the company incorporates by reference.

*Frequencies are defined as: very common (=> 1/10); common
(=> 1/100, < 1/10); uncommon (=> 1/1,000, < 1/100); rare (=> 1/10,000,
< 1/1,000); and very rare (< 1/10,000).

(1) JANUVIA is a registered trademark of Merck & Co., Inc., which
operates in many countries as MSD (Merck, Sharp & Dohme).