Moxilubant is an orally active leukotriene B4 antagonist patented by Ciba-Geigy A.-G. and studied for psoriasis, rheumatoid arthritis, and chronic obstructive pulmonary disease treatment. Moxilubant inhibits LTB4 signaling with a potency of 2–4 nM. In a phase 1 study in 10 healthy volunteers, Moxilubant was administered orally once or twice daily for 7 days at doses ranging from 100 to 500 mg. At dose levels of 150 mg and above, LTB4 pathway inhibition reached at least 75%. At doses of 300 mg and above, pathway inhibition reached 100%. A Phase 2 study was conducted in 24 patients with COPD treated with 240 mg/day Moxilubant for 4 weeks. In this study, there were no changes in sputum cell counts or biomarkers or in spirometry measures, even though plasma levels of Moxilubant were sufficient to significantly reduce pathway signaling.