In vitro and in vivo immunopharmacological profile of Sch 40120.

Sch 40120 (10-(3-chlorophenyl) - 6,8,9,10- tetrahydrobenzo [b] [1,8] naphthyridin-5 (7H)-one) is a leukotriene inhibitor that is also a potent inhibitor of acute inflammatory responses in rodent systems. In the present study, we have evaluated the effects of this drug on immune function as well as its activity in models of immune mediated chronic inflammatory disease. Sch 40120 was particularly effective in suppressing T cell proliferative responses in vitro. Antigen-specific and poly-clonally-induced in vitro antibody responses were also inhibited by the drug. However, the in vivo potency of Sch 40120 in suppressing immune responses and in inhibiting the pathological changes seen in rodent models of autoimmune disease (EAE and adjuvant arthritis) was somewhat less than that previously observed in models of acute inflammation. Nevertheless, the spectrum of activities exhibited by Sch 40120 suggests that it will be particularly useful in the treatment of psoriasis where T lymphocytes have been implicated in the development of disease and leukotrienes appear to have a role in the persistence of psoriatic plaques.