MannKind has capped years of research and three FDA rejections with a positive: regulatory approval of its inhaled insulin, Afrezza.

The mealtime human insulin is for type 1 and type 2 diabetes patients, and type 1 patients are instructed to use it in tandem with long-acting insulin.

Last week’s approval followed the regulator’s April request for more time to ponder the data, and this request followed an unexpected endorsement by an FDA advisory panel this past spring. It was a surprise because pre-meeting documentation seemed to indicate the panel was not feeling favorable towards the drug.

The new drug includes a black-box warning which notes COPD and other chronic lung disease patients should stay away from Afrezza because it’s been associated with acute bronchospasm. Griffin Securities analyst Keith Markey is not bothered by the warning, telling Bloomberg he considered it a “non-event,” because “MannKind never wanted to market it to people with COPD.”

The approval also includes post-marketing study requirements that will address topics including pediatric use and cardiovascular risk.