Merck Demonstrates Continued Commitment to Advancing Hepatitis Therapy at European Association for the Study of the Liver (EASL) 2010 Annual Meeting

Merck Demonstrates Continued Commitment to Advancing Hepatitis Therapy at European Association for the Study of the Liver (EASL) 2010 Annual Meeting

Wednesday, April 14, 2010

VIENNA, Austria - Merck & Co., Inc., Whitehouse Station, N.J., U.S.A., demonstrated its ongoing commitment to hepatitis therapy at the 45th annual meeting of the European Association for the Study of the Liver (EASL) in Vienna, Austria, presenting data on the company’s comprehensive portfolio of marketed products and investigational direct acting antiviral (DAA) compounds in development for the treatment of chronic hepatitis C. Hepatitis C virus (HCV) infection is a serious, potentially life-threatening disease that affects nearly 4 million people in the United States, 4 million in Europe and approximately 170 million people worldwide. It is the leading cause of cirrhosis and liver cancer, and the primary reason for liver transplants in the United States and Europe.

Merck completed its merger with Schering-Plough Corporation on Nov. 3, 2009, and the company is continuing Schering-Plough’s work in the hepatitis field. For more than 20 years, Schering-Plough has been a leader in the development of innovative therapies that significantly advanced treatment for hepatitis B and C. Merck has been a pioneer in the field through its development of vaccines for the prevention of hepatitis A and B.

“Today, with our combined portfolio, the new Merck is committed to continuing this legacy and to being a leader in the development of vaccines and pharmaceuticals to both prevent and treat viral hepatitis,” said Patrick Bergstedt, senior vice president and general manager, Merck Infectious Diseases. “Our vision in hepatitis C is to continue to be a global leader in the discovery, development, and delivery of therapies that advance patient care, including the development of oral combination therapies.”

Hepatitis C is a key area for current and future investment at Merck. Extensive research efforts are underway to develop differentiated compounds that bring innovation to hepatitis care. These compounds include HCV protease inhibitors and compounds acting through other complementary mechanisms to block HCV replication.

Merck’s HCV portfolio includes:

* PEGINTRON® (peginterferon alfa-2b) and REBETOL® (ribavirin, USP) combination therapy, approved and marketed for treating chronic hepatitis C.


* Boceprevir, the company’s lead investigational HCV protease inhibitor currently in Phase III clinical development. The boceprevir Phase III registration trials are fully enrolled. Merck expects to conclude its pivotal Phase III studies in mid-2010 and to submit an NDA by the end of 2010 for both treatment-experienced and treatment-naïve patients with genotype 1 chronic hepatitis C.


* Vaniprevir (formerly known as MK-7009), the company’s lead follow-on HCV protease inhibitor currently in Phase IIb clinical development.


* Narlaprevir, also an investigational HCV protease inhibitor, is completing a proof-of-concept study and will serve as a potential back-up to vaniprevir.


* MK-5172, a second-generation HCV NS3/4a protease inhibitor in Phase I development.


For more information about Merck data presentations at EASL Vienna 2010, please visit the EASL Web site at: http://www2.kenes.com/liver-congress/Pages/Home.aspx.

For Merck press releases on boceprevir, please visit the Merck newsroom at:http://www.merck.com/newsroom/home.html, search term boceprevir.

For more information about ongoing boceprevir clinical studies, please visitwww.clinicaltrials.gov.

About PEGINTRON
PEGINTRON is indicated for use in combination with REBETOL (ribavirin) for the treatment of chronic hepatitis C in patients 3 years of age and older with compensated liver disease.

The following points should be considered when initiating therapy with PEGINTRON in combination with REBETOL: (1) These indications are based on achieving undetectable HCV RNA after treatment for 24 or 48 weeks and maintaining a Sustained Virologic Response (SVR) 24 weeks after the last dose. (2) Patients with the following characteristics are less likely to benefit from re-treatment after failing a course of therapy: previous nonresponse, previous pegylated interferon treatment, significant bridging fibrosis or cirrhosis, and genotype 1 infection. (3) No safety and efficacy data are available for treatment of longer than one year.

PEGINTRON is also indicated for use alone for the treatment of chronic hepatitis C in patients with compensated liver disease previously untreated with interferon alpha and who are at least 18 years of age.

The following points should be considered when initiating therapy with PEGINTRON alone: Combination therapy with REBETOL is preferred over PEGINTRON monotherapy unless there are contraindications to, or significant intolerance of, REBETOL. Combination therapy provides substantially better response rates than monotherapy.

Important Safety Information on PEGINTRON

WARNING: RISK OF SERIOUS DISORDERS AND RIBAVIRIN-ASSOCIATED EFFECTS
Alpha interferons, including PEGINTRON, may cause or aggravate fatal or life-threatening neuropsychiatric, autoimmune, ischemic, and infectious disorders. Patients should be monitored closely with periodic clinical and laboratory evaluations. Patients with persistently severe or worsening signs or symptoms of these conditions should be withdrawn from therapy. In many, but not all cases, these disorders resolve after stopping PEGINTRON therapy.

Use with Ribavirin: Ribavirin may cause birth defects and death of the unborn child. Extreme care must be taken to avoid pregnancy in female patients and in female partners of male patients. Ribavirin causes hemolytic anemia. The anemia associated with REBETOL therapy may result in a worsening of cardiac disease. Ribavirin is genotoxic and mutagenic and should be considered a potential carcinogen.


Contraindications
PEGINTRON is contraindicated in patients with known hypersensitivity reactions such as urticaria, angioedema, bronchoconstriction, anaphylaxis, Stevens-Johnson syndrome and toxic epidermal necrolysis to interferon alpha or any other component of the product, autoimmune hepatitis, and hepatic decompensation (Child-Pugh score more than 6 [class B and C]) in cirrhotic CHC patients before or during treatment. PEGINTRON/REBETOL combination therapy is additionally contraindicated in women who are pregnant or may become pregnant (see Boxed Warning and Pregnancy section), men whose female partners are pregnant, patients with hemoglobinopathies (e.g., thalassemia major, sickle-cell anemia), and patients with creatinine clearance less than 50 mL per min.

Pregnancy
REBETOL therapy should not be started until a report of a negative pregnancy test has been obtained immediately prior to planned initiation of therapy. Extreme care must be taken to avoid pregnancy in female patients and in female partners of male patients during therapy and six months post-treatment. Patients should use at least two effective forms of contraception and have monthly pregnancy tests during therapy and for six months after completion of therapy. If this drug is used during pregnancy or if a patient becomes pregnant, the patient should be apprised of the potential hazard to a fetus. A Ribavirin Pregnancy Registry has been established to monitor maternal-fetal outcomes of pregnancies in female patients and female partners of male patients exposed to ribavirin during treatment, and for six months following cessation of treatment. Physicians and patients are encouraged to report such cases by calling 1-800-593-2214.

Incidence of Adverse Events
Most common adverse reactions (more than 40%) in adult patients receiving either PEGINTRON or PEGINTRON/REBETOL are injection site inflammation/reaction, fatigue/asthenia, headache, rigors, fevers, nausea, myalgia, and anxiety/emotional lability/irritability. Most common adverse reactions (more than 25%) in pediatric patients receiving PEGINTRON/REBETOL are pyrexia, headache, neutropenia, fatigue, anorexia, injection site erythema, and vomiting.

In a study with PEGINTRON/REBETOL (weight-based) combination therapy in adult patients, anemia with weight-based dosing was 29%; however, the majority of these cases were mild and responded to dose reductions. The incidence of serious adverse reactions reported for the weight-based REBETOL group was 12%. In many but not all cases, adverse reactions resolved after dose reduction or discontinuation of therapy. Some patients experienced ongoing or new serious adverse reactions during the 6-month follow-up period. Discontinuations for adverse events were 15% and were related to known interferon effects of psychiatric, systemic (e.g., fatigue, headache), or gastrointestinal adverse reactions. Dose modifications due to adverse reactions occurred in 29% of patients.

Most common adverse reactions with PEGINTRON/REBETOL (weight-based) combination therapy were psychiatric, which occurred among 68-69% of patients. These psychiatric adverse reactions included most commonly depression, irritability, and insomnia, each reported by approximately 30-40% of subjects in all treatment groups. Suicidal behavior (ideation, attempts, and suicides) occurred in 2% of all patients during treatment or during follow-up after treatment cessation. PEGINTRON induced fatigue or headache in approximately two-thirds of patients, with fever or rigors in approximately half of the patients. The severity of some of these systemic symptoms (e.g., fever and headache) tends to decrease as treatment continues. There was a 23-24% incidence overall for injection site reactions or inflammation.

Individual serious adverse reactions occurred at a frequency 1% and included suicide attempt, suicidal ideation, severe depression; psychosis, aggressive reaction, relapse of drug addiction/overdose; nerve palsy (facial, oculomotor); cardiomyopathy, myocardial infarction, angina, pericardial effusion, retinal ischemia, retinal artery or vein thrombosis, blindness, decreased visual acuity, optic neuritis, transient ischemic attack, supraventricular arrhythmias, loss of consciousness; neutropenia, infection (sepsis, pneumonia, abscess, cellulitis); emphysema, bronchiolitis obliterans, pleural effusion, gastroenteritis, pancreatitis, gout, hyperglycemia, hyperthyroidism and hypothyroidism, autoimmune thrombocytopenia with or without purpura, rheumatoid arthritis, interstitial nephritis, lupus-like syndrome, sarcoidosis, aggravated psoriasis, urticaria, injection site necrosis, vasculitis, and phototoxicity.

Additional serious adverse events included suicide, homicidal ideation, aggressive behavior sometimes directed towards others, hallucinations, bipolar disorders, mania, encephalopathy (usually elderly treated with higher doses of PEGINTRON), hypotension, tachycardia, retinopathy including macular edema, retinal hemorrhage, cotton wool spots, papilledema, serous retinal detachment, ischemic and hemorrhagic cerebrovascular events, bone marrow toxicity (cytopenia and very rarely aplastic anemia), thyroiditis, dental and periodontal disorders, hemorrhagic/ischemic colitis, dyspnea, pulmonary infiltrates, pneumonia, interstitial pneumonitis, pulmonary hypertension, hepatic failure, increases in serum creatinine in patients with renal insufficiency, acute hypersensitivity (angioedema, bronchoconstriction, anaphylaxis and cutaneous eruptions), hypertriglyceridemia, and peripheral neuropathy.

During the course of therapy lasting up to 48 weeks in patients ages 3 through 17 years receiving PEGINTRON/REBETOL combination therapy, weight loss and growth inhibition were common.

Please see full prescribing information at http://www.spfiles.com/pipeg-intron.pdf.

About Merck
Today’s Merck is working to help the world be well. Through our medicines, vaccines, biologic therapies, and consumer and animal products, we work with customers and operate in more than 140 countries to deliver innovative health solutions. We also demonstrate our commitment to increasing access to healthcare through far-reaching programs that donate and deliver our products to the people who need them. Merck. Be Well. For more information, visitwww.merck.com.

Forward-Looking Statement
This news release includes “forward-looking statements” within the meaning of the safe harbor provisions of the United States Private Securities Litigation Reform Act of 1995. Such statements may include, but are not limited to, statements about the benefits of the merger between Merck and Schering-Plough, including future financial and operating results, the combined company’s plans, objectives, expectations and intentions and other statements that are not historical facts. Such statements are based upon the current beliefs and expectations of Merck’s management and are subject to significant risks and uncertainties. Actual results may differ from those set forth in the forward-looking statements.

The following factors, among others, could cause actual results to differ from those set forth in the forward-looking statements: the possibility that the expected synergies from the merger of Merck and Schering-Plough will not be realized, or will not be realized within the expected time period, due to, among other things, the impact of pharmaceutical industry regulation and pending legislation that could affect the pharmaceutical industry; the risk that the businesses will not be integrated successfully; disruption from the merger making it more difficult to maintain business and operational relationships; Merck’s ability to accurately predict future market conditions; dependence on the effectiveness of Merck’s patents and other protections for innovative products; the risk of new and changing regulation and health policies in the U.S. and internationally and the exposure to litigation and/or regulatory actions.

Merck undertakes no obligation to publicly update any forward-looking statement, whether as a result of new information, future events or otherwise. Additional factors that could cause results to differ materially from those described in the forward-looking statements can be found in Merck’s 2009 Annual Report on Form 10-K and the company’s other filings with the Securities and Exchange Commission (SEC) available at the SEC’s Internet site (www.sec.gov).