Merck Provides Preliminary Analyses of the Completed MEDAL Program for ARCOXIA(TM) (Etoricoxib); Merck Looks Forward to Reviewing the MEDAL Program Data with Regulatory Agencies and Intends To Respond to FDA-Issued ''Approvable'' Letter.

WHITEHOUSE STATION, N.J. -- Full Results of the MEDAL Program Will Be Disclosed in a Scientific Peer-Reviewed Publication and in Presentations at Scientific Meetings

Merck & Co., Inc. announced today that preliminary analyses indicate the MEDAL (Multinational Etoricoxib and Diclofenac Arthritis Long-Term) Program showed that the rate of confirmed thrombotic cardiovascular (CV) events was similar between the selective COX-2 inhibitor ARCOXIA(TM) and diclofenac, a traditional nonsteroidal anti-inflammatory drug (NSAID). Specifically, in the pre-specified "per-protocol" analysis of the primary endpoint, the relative risk of confirmed thrombotic CV events between ARCOXIA and diclofenac was 0.95 (95 percent CI: 0.81, 1.11). In the "intent-to-treat" analysis, the relative risk of confirmed thrombotic CV events between ARCOXIA and diclofenac was 1.05 (95 percent CI: 0.93, 1.19), consistent with the primary per-protocol analysis.

The MEDAL Program consists of three studies of ARCOXIA 60 mg or 90 mg in osteoarthritis and rheumatoid arthritis patients (MEDAL, EDGE and EDGE II). In the MEDAL study (the largest component of the MEDAL Program), the incidence of discontinuations due to hypertension-related adverse events was significantly higher for ARCOXIA compared to diclofenac. Also in the MEDAL study, the incidence of discontinuations due to edema-related adverse events was significantly higher only for ARCOXIA 90 mg compared to diclofenac, and the incidence of adjudicated and confirmed cases of congestive heart failure trended higher only for ARCOXIA 90 mg compared to diclofenac. The incidence of discontinuations due to a composite endpoint of clinical gastrointestinal adverse events and hepatic adverse events was significantly higher for diclofenac compared to ARCOXIA in the MEDAL study. These findings from the MEDAL study are consistent with the previously disclosed findings from the EDGE study, which are described in European labeling for ARCOXIA.

"After four years of conducting this arthritis study program in more than 34,000 patients, we are looking forward to sharing the full MEDAL Program results in the future," said Dr. Peter S. Kim, president, Merck Research Laboratories.

Analyses of the data are ongoing. As previously planned, full results of the MEDAL Program, which began in 2002, will be disclosed in a scientific peer-reviewed publication and in presentations at scientific meetings. The final analyses that will be in publication are being verified by an independent statistical center. Preliminary analyses from the MEDAL Program recently were provided to the European Medicines Agency (EMEA), the U.S. Food and Drug Administration (FDA) and other regulatory agencies in countries where ARCOXIA is approved or under review. The Company looks forward to reviewing the data with all of these agencies. The Company intends to respond to the "approvable" letter issued by the FDA, and will include the results of the MEDAL Program as part of that response.

About the MEDAL Program

Conducted in 38 countries, the MEDAL Program is the first arthritis study program designed with CV safety as its primary endpoint, and is the largest and longest controlled clinical assessment of a selective COX-2 inhibitor vs. a traditional NSAID in an arthritis patient population.

As its primary objective, the MEDAL Program was designed to perform a non-inferiority analysis of confirmed thrombotic (blood-clotting) CV events following daily treatment of ARCOXIA (60 or 90 mg daily) or diclofenac (150 mg daily) in osteoarthritis (OA) and rheumatoid arthritis (RA) patient populations. Diclofenac is the most widely prescribed traditional NSAID in the world.

The MEDAL Program was a prospectively designed clinical program combining CV safety data from three trials - the MEDAL, EDGE and EDGE II studies. The MEDAL study, the longest of the three studies, was an event-driven CV outcomes study that included data in more than 23,000 OA and RA patients. The primary hypothesis of the MEDAL Program was that in the treatment of patients with OA and RA, ARCOXIA 60 or 90 mg would be non-inferior or "no worse than" diclofenac 150 mg daily based on confirmed thrombotic CV events. The pre-specified criterion for non-inferiority in the MEDAL Program was an upper bound of a two-sided 95 percent confidence interval below 1.30.

About ARCOXIA

ARCOXIA is Merck & Co., Inc.'s selective COX-2 inhibitor for arthritis and pain. The FDA issued an "approvable" letter on the New Drug Application for ARCOXIA in October 2004. ARCOXIA is currently available in 62 countries in Europe, Latin America, the Asia-Pacific region and Middle East/Northern Africa.

About Merck

Merck & Co., Inc. 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.

Forward-Looking Statement

This press release, including the attachment, 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.

ARCOXIA(TM) is a trademark of Merck & Co., Inc.

Fact Sheet on Design and Methodology of the MEDAL Program is attached.

FACT SHEET ON DESIGN AND METHODOLOGY OF THE MEDAL PROGRAM
       SOURCE: AMERICAN HEART JOURNAL (August 2006; 152:237-45)
                            by Cannon et al

 "Clinical trial design and patient demographics of the Multinational
 Etoricoxib and Diclofenac Arthritis Long-Term (MEDAL) Study Program:
 Cardiovascular outcomes with etoricoxib versus diclofenac in patients
             with osteoarthritis and rheumatoid arthritis"

Objective and Components of the MEDAL Program

--The MEDAL Program was a prospectively designed clinical program combining cardiovascular (CV) safety data from three trials - the MEDAL, EDGE and EDGE II studies.

--As the pre-specified primary endpoint, the MEDAL Program was designed to perform a non-inferiority analysis of confirmed thrombotic CV events following daily treatment with ARCOXIA (60 or 90 mg daily) or the traditional nonsteroidal anti-inflammatory drug (NSAID) diclofenac (150 mg daily) in an arthritis patient population combining data from all three component studies.

--  The MEDAL study was an event-driven CV outcomes study that
            included data from more than 23,000 osteoarthritis (OA)
            and rheumatoid arthritis (RA) patients.

        --  EDGE was a one-year gastrointestinal (GI) tolerability
            study in 7,111 OA patients, with CV safety designated as a
            pre-specified secondary endpoint. Results were announced
            in October 2004.

        --  EDGE II was a two-and-a-half-year GI tolerability study in
            4,086 RA patients, with CV safety designated as a
            pre-specified secondary endpoint.

Patient Population

--The MEDAL Program was designed to enroll OA and RA patients who are routinely encountered in clinical practice and require chronic therapy.

--  Eligible patients were at least 50 years of age and
            clinically diagnosed with OA or RA.

        --  Based on judgment of the investigator, eligible patients
            required chronic therapy, either with a traditional NSAID
            or selective COX-2 inhibitor.

--The MEDAL Program enrolled OA and RA patients with a range of CV risks.

--  Approximately 38 percent of participants enrolled in the
            MEDAL Program were at increased CV risk at baseline
            (defined as having at least two cardiac risk factors
            and/or a history of symptomatic atherosclerotic CV
            disease).

        --  Approximately 35 percent of patients in the MEDAL Program
            are low-dose aspirin users.

Duration of Treatment

--Results from the MEDAL Program will include data in more than 34,000 arthritis patients with a median treatment time of approximately 17 months; more than one-third of patients (more than 10,000) had more than 24 months of exposure with some patients receiving up to 40 months of exposure. The MEDAL Program will provide the largest amount of long-term CV safety data for any selective COX-2 inhibitor or traditional NSAID (excluding low-dose aspirin) currently available.

Study Comparator

--The chosen control in the MEDAL Program is the most widely used prescription NSAID in the world, diclofenac.

--Diclofenac is an effective treatment for both OA and RA.

--Diclofenac does not possess sustained anti-platelet effects, like naproxen, nor does it interfere with the anti-platelet effects of aspirin, like ibuprofen.

--Diclofenac is documented to be a dual inhibitor of both COX-1 and COX-2 at therapeutic doses.

--Like other traditional NSAIDs, diclofenac significantly increases the incidence of gastroduodenal ulcers compared to placebo and selective COX-2 inhibitors.

End of Fact Sheet