MannKind Corporation announced it has started enrolling patients in its phase 3 safety trial of inhaled TechnoSphere Insulin in the United States. In late 2004, the company started another phase 3 efficacy study in Europe. The Valencia company is one of several around the country working on an inhaled insulin delivery system. MannKind is the furthest behind in development, but analysts have predicted that the market will be large enough to provide very lucrative opportunities for any company that can successfully bring an inhaled insulin product to market. In anticipation of future filings and commercialization, the company is also building up its manufacturing facilities in Valencia.