SCHERING LEUKOTRIENE ANTAGONIST SCH 37224 ENTERING PHASE II

SCHERING LEUKOTRIENE ANTAGONIST SCH 37224 ENTERING PHASE II study for the treatment of allergic rhinitis during the first quarter of 1989, the company told securities analysts at a Nov. 30 meeting in Kenilworth, New Jersey. The efficacy study will be conducted in the southwestern U.S. using cedar as the allergen.

A Phase II pilot study for asthma is also planned. Schering-Plough management predicted that SCH 37224 would move into Phase III studies for allergic rhinitis in 1990 and for asthma in 1991.

Leukotriene antagonist research is one of three directions that Schering-Plough is pursuing in the anti-allergy area. The company's emphasis on antagonists of allergic response mediators also includes work on histamine and platelet activating factor (PAF), which is a lipid mediator substance.

The most advanced compound out of Schering's histamine research is Claritin (loratadine), a non-sedating antihistamine currently in the final stages of FDA review. The company expects the product to eventually add as much as $300 mil. annually to its prescription anti-allergy line. In 1987, asthma/allergy and cold products accounted for $627 mil. in worldwide sales, or about one-third of Schering's $1.9 bil. pharmaceutical volume.

The company also used the occasion of its yearly analyst presentation to disclose, for the first time, work on the PAF-antagonist SCH 37370. Multiple-dose Phase I studies are expected to begin in 1989, with subsequent efficacy studies planned for asthma, rhinitis and chronic urticaria. Based on clinical work that began in 1985, SCH 37370 is a potential once-a-day drug that can block both PAF-induced and histamine-induced bronchoconstriction.