Pink Sheet is part of Informa PLC

This site is operated by a business or businesses owned by Informa PLC and all copyright resides with them. Informa PLC’s registered office is 5 Howick Place, London SW1P 1WG. Registered in England and Wales. Number 8860726.

This copy is for your personal, non-commercial use. For high-quality copies or electronic reprints for distribution to colleagues or customers, please call +44 (0) 20 3377 3183

Printed By



Executive Summary

MERCK LEUKOTRIENE ANTAGONIST MK-571 ASTHMA CLINICALS should reach publication stage in 1990, Anthony Ford-Hutchinson of the Merck Frosst Centre for Therapeutic Research reported at a recent conference on allergic disease. MK-571 is one of the lead leukotriene compounds being studied by Merck at the Canadian research facility. The compound is a leukotriene D4 receptor antagonist. The allergy conference, sponsored by International Business Communications, took place in Boston Oct. 3-4. According to Dr. Hutchinson, "while several mediators have been suggested as possible factors in causing asthma, leukotriene D4 may play a major role, since it has been found to induce multiple pathologic airway responses in studies involving human tissue." In particular "leukotriene D4 induces smooth muscle contraction in human peripheral airways, . . . causes bronchoconstriction when inhaled, . . . increases the release of mucous in human airways, . . . and has been shown to induce bronchial hyperreactivity when administered by aerosol to asthmatic patients." According to Hutchinson, "MK-571 (formerly L-660, 711) is an example of a new class of potent leukotriene D4 receptor antagonists," and appears to inhibit the binding of leukotriene D4 to human lung homogenates selectively. The compound is believed to be in Phase II development. Having been shown to be "well-tolerated (when) administered intravenously in normal and asthmatic subjects in single doses of 15 to 1500 mg," and "shown to inhibit leukotriene D4-induced bronchoconstriction" in six healthy male volunteers, "MK-571 is currently being evaluated in asthmatics with and without bronchial provocation," Hutchinson reported. Intravenous, oral and aerosolized forms of the compound are all being examined, the Merck researcher observed. Another Merck leukotriene-related substance currently in clinical trials under the auspices of the Merck Frosst Centre is MK-886, an inhibitor of leukotriene biosynthesis rather than a receptor antagonist. In contrast to the receptor antagonists, MK-886 is believed to prevent the synthesis of leukotriene D4 within cells by preventing the activation of 5-lipoxygenase, an enzyme pathway through which the production of leukotrienes is catalyzed. Without discussing particulars of clinical trials, Hutchinson stated that "clinical studies in man with MK-886 will help define the role of leukotrienes in a variety of pathological processes including bronchial asthma, and comparative studies with MK-571 will provide information as to the relative importance of other leukotrienes than leukotriene D4, such as leukotriene B4."

You may also be interested in...

Part D Discount Liability Coming Into Focus: CMS Releases Drug Cost Data

Newly released Medicare Part D data sheds light on the sales hit that branded pharmaceutical manufacturers will face when the coverage gap discount program gets under way in 2011

FDA Skin Infections Guidance Spurs Debate On Endpoint Relevance

FDA appears headed for a showdown with clinicians and the pharmaceutical industry over the proposed new clinical trial endpoints for acute bacterial skin and skin structure infections, the guidance's approach for justifying a non-inferiority margin and proposed changes in the types of patients that should be enrolled in trials

Shire Hopes To Sow Future Deals With $50M Venture Fund

Specialty drug maker Shire has quietly begun scouting deals with a brand-new $50 million venture fund, the latest of several in-house investment arms to launch with their parent company's pipelines, not profits, as the measure of their worth




Ask The Analyst

Ask the Analyst is free for subscribers.  Submit your question and one of our analysts will be in touch.

Your question has been successfully sent to the email address below and we will get back as soon as possible. my@email.address.

All fields are required.

Please make sure all fields are completed.

Please make sure you have filled out all fields

Please make sure you have filled out all fields

Please enter a valid e-mail address

Please enter a valid Phone Number

Ask your question to our analysts