Actelion Ltd, a biopharmaceutical company, discovers, develops, and commercializes low molecular weight drugs for unmet medical needs. It sells Tracleer, an endothelin receptor antagonist for the treatment of pulmonary arterial hypertension (PAH); Opsumit, an orally available endothelin receptor antagonist; and Ventavis, an inhaled formulation of iloprost, a synthetic compound structurally similar to prostacyclin. The company also provides Veletri, an intravenous prostacyclin for the treatment of PAH to enhance exercise capacity; Zavesca, an oral capsule for the treatment of patients with mild to moderate type 1 Gaucher disease for whom enzyme replacement therapy is not a therapeutic option; Valchlor, a topical formulation of mechlorethamine for the treatment of stage IA and IB mycosis fungoides-type cutaneous T-cell lymphoma in patients; and Uptravi, an oral selective IP receptor agonist targeting the prostacyclin pathway in PAH. Actelion Ltd markets its products in Switzerland, the United States, Europe, Japan, and internationally. The company was founded in 1997 and is headquartered in Allschwil, Switzerland. Actelion Ltd operates as a subsidiary of Johnson & Johnson Management Limited