[Protective effect of KW-2228 in a systemic infection model of CPA-treated tumor-bearing mice].

A modified recombinant human granulocyte colony-stimulating factor (rhG-CSF), KW-2228, has some excellent properties such as high specific activity in stimulating granulocyte colony-formation in vitro, great biological stability in plasma, good pharmacokinetic profile and high potency in granulopoiesis in normal mice in vivo. Recently, the application of G-CSF against infectious diseases has been considered, and some animal experiments have been carried out to support its in clinical applications. Patients with underlying diseases such as leukemia or cancer often have recurrent infections because of reduced number and functions of neutrophils, which mediate an early stage of host defense. We investigated the prophylactic effect of KW-2228 against an experimental systemic infection with Pseudomonas aeruginosa in tumor-bearing mice (colon 26: BALB/c) treated with cyclophosphamide. KW-2228 (0.25-2.0 micrograms/mouse) was administered (s.c.) once a day for 4 days before the experimental bacterial infection. As a result of KW-2228 administration, the reduction in peripheral blood neutrophils usually caused by the injection with cyclophosphamide was prevented markedly. KW-2228 displayed excellent protective potency dose-dependently against the infection with P. aeruginosa in tumor-bearing mice. These data show the possibility that prophylactic therapy with KW-2228 may augment the host defense of immunocompromised patients to infections. It present, clinical efficacy studies on KW-2228 are under way.