Merck discloses four new product candidates in research and development.

RAHWAY, N.J.--(BUSINESS WIRE)--May 21, 1996--Merck & Co., Inc., today made public four major new product candidates, which are in clinical trials, at a briefing for securities analysts at Merck Research Laboratories in Rahway, New Jersey: two anti-inflammatory compounds for osteoarthritis and other possible indications, an anti-fungal agent, and an antibiotic. Company scientists also discussed several of the other investigational medicines in the pipeline, new developments with marketed medicines, and two major basic research programs. These developments follow Food and Drug Administration clearances of a record eight new Merck medicines in 14 months.

Raymond V. Gilmartin, Chairman, President and Chief Executive Officer of the Company, introduced the session which was moderated by Edward M. Scolnick, M.D., Executive Vice President, Science and Technology and President, Merck Research Laboratories. The presenters were Eve Slater, M.D., Senior Vice President, Clinical & Regulatory Development; Reynold Spector, M.D., Senior Vice President, Clinical Sciences; Bennett Shapiro, M.D., Executive Vice President, Worldwide Basic Research, and C. Thomas Caskey, M.D., Senior Vice President, Worldwide Basic Research.

Four New Product Candidates

The anti-inflammatory compound, MK-966, selectively inhibits the enzyme in the body, called COX-2, which is involved in pain, inflammation and fever. The non-steroidal anti-inflammatory drugs (NSAIDs) which are now on the market, such as ibuprofen, inhibit both the COX-2 enzyme and the COX-1 enzyme which is involved in maintaining normal gastrointestinal function. That is why NSAIDs are associated with gastrointestinal toxicity, with a 2% incidence of gastroduodenal ulcers, perforations and bleeding, resulting in 76,000 hospitalizations and 7,600 deaths per year in the U.S. alone. The selective inhibition of COX-2 by MK-966 offers the potential to produce significant analgesic and anti-inflammatory benefits with fewer gastrointestinal side effects. MK-966 is in Phase II (small-scale efficacy) trials and will be evaluated in large-scale studies for the treatment of osteoarthritis, rheumatoid arthritis and other inflammatory diseases. A second member of this new class of medicines, L-752,860, has even greater selectivity for COX-2 and it is in Phase I safety trials.

A new anti-fungal compound, L-743,872, is in ongoing Phase I clinical trials. Utilizing a new mode of action and demonstrating a wide microbiologic spectrum, the compound has potent fungicidal activity against Candida (including azole-resistant candida), Aspergillus and other fungi. Candida accounts for approximately 80% of all major systemic fungal infections. L-743,872 inhibits glucan synthase, an enzyme important in maintaining the fungal cell wall. L-743,872 is administered intravenously once daily, and has been generally well tolerated in early Phase I studies.

L-749,345, a broad-spectrum, injectable antibiotic of the carbapenem class, is in early clinical development. L-749,345 will be evaluated for effectiveness against many bacterial infections including those of the urinary tract, the lower respiratory tract and the abdomen. This easy-to-administer, once- or twice-a-day compound will also be evaluated as outpatient, follow-up therapy to the short-acting carbapenems and as a preventive treatment prior to surgery.

Progress on Two New Vaccines

A human papillomavirus (HPV) vaccine for the prevention of genital warts and cervical cancer in adults is being prepared for Phase I trials. The proposed product candidate is a genetically engineered (recombinant) vaccine that contains purified proteins from the outer coat of the virus.

Merck's pediatric pneumococcal conjugate vaccine to treat middle-ear infection, meningitis, pneumonia and bloodstream infections is in Phase III (large-scale efficacy) studies. Targeted to more than 80% of pathogenic strains of Streptococcus pneumoniae, the vaccine, administered alone or in combination with other pediatric vaccines, is highly effective in studies to date in producing immunity in infants.

Ongoing Clinical Development Candidates

Merck's growth hormone secretagogue, MK-677, is now being evaluated in Phase II trials involving growth-hormone-deficient children, the elderly with muscle weakness and those who are recovering from hip fractures. It is also being evaluated in combination with Merck's Fosamax. (alendronate) in patients with osteoporosis.

Aggrastat (tirofiban), a non-peptide platelet blocker for the treatment of unstable angina and cardiac complications associated with balloon angioplasty, is in Phase III trials with regulatory filings expected in the second half of 1997. Maxalt (rizatriptan), a serotonin 5HTID agonist under development for the treatment of migraine attacks and associated symptoms, is in Phase III studies with a target New Drug Application (NDA) filing date of mid-1997. Singulair. (montelukast), an oral leukotriene receptor antagonist under development for the treatment of asthma, is on target for NDA filing in the first quarter of 1997. Phase II trial data on Propecia. (finasteride), under development for the treatment of male pattern baldness, demonstrated a significant improvement in hair count and hair growth, and the NDA will be filed in the fourth quarter of this year.

New Developments with Marketed Medicines

Company scientists also overviewed ongoing research with marketed prescription medicines. The U.S. Food and Drug Administration approved a labeling change for Cozaar( (losartan), Merck's angiotensin II antagonist for the treatment of hypertension, stating that the incidence of cough is similar to that with hydrochlorothiazide or placebo in a population that had cough in association with ACE inhibitor therapy. Mevacor(, one of Merck's cholesterol-lowering drugs, received clinical pharmacology labeling based upon the so-called ACAPS trial in which Mevacor( produced a significant regression of carotid lesions, as well as significant reductions in major cardiovascular events and deaths ("all-cause mortality"). Additional strengths of Zocor( (simvastatin), currently the largest-selling cholesterol medicine worldwide, are targeted for filing in mid-1997. A supplement for a new indication was filed in the U.S. for Fosamax( (alendronate) on April 29, 1996, for the prevention of osteoporosis in postmenopausal women.

A supplement for a 30-minute prevention claim was filed with the FDA on March 29, 1996 for Pepcid AC Acid Controller, which is marketed by the joint venture company, Johnson & Johnson(Merck. Long-term studies continue with Crixivan( (indinavir), Merck's new protease inhibitor for the treatment of HIV disease, to evaluate its effect on disease progression and survival. A pediatric formulation of Crixivan( is being developed.

Basic Research Programs in Cancer and Genome Science

Merck's cancer research initiative has yielded new insights about cellular growth regulation, and many potential targets have emerged, including oncogenes (genes that cause abnormal growth) and tumor suppressor genes (genes that keep growth in check). Merck is using gene biology to develop compounds that inhibit the activation of oncogenes by a process involving the RAS protein which is associated with many tumors.

Long-term initiatives in DNA vaccines, genomics and gene therapy were previewed. Merck's DNA vaccine program covers several disease targets, including influenza (for which Phase I studies have been initiated), herpes (clinical studies are expected to begin in early 1997), and AIDS. Merck just entered into a collaborative research and licensing agreement with the University of Oxford and The Wellcome Trust for the discovery of human genes associated with the development of Type I diabetes, or Insulin Dependent Diabetes Mellitus (IDDM).

Merck & Co., Inc. is a leading research-driven pharmaceutical products and services company. Merck discovers, develops, manufactures and markets a broad range of innovative products to improve human and animal health. Merck-Medco Managed Care Inc. manages pharmacy benefits for approximately 47 million Americans, encouraging the appropriate use of medicines and providing health management programs. Through these complementary capabilities, Merck works to improve quality of life and contain overall health-care costs. In addition to delivering these benefits to society, Merck is committed to providing superior returns for shareholders and a stimulating work environment for employees.

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