Asthma affects more than 300 million people worldwide, causing variable symptoms of cough, chest tightness, and exertional or nocturnal dyspnea due to chronic inflammation of the lower airways and bronchial hyperresponsiveness. Acute episodes of worsening respiratory symptoms, called acute exacerbations or asthma attacks, can be life-threatening, and induce important costs, encompassing both direct health care expenses and indirect costs due to absence from work or school. For many decades, asthma attacks have been treated with inhaled short-acting bronchodilators and systemic corticosteroids. There is thus a need for novel therapies which—as add-on treatment to systemic corticosteroids—could hasten clinical and functional recovery in patients experiencing an asthma attack and prevent complications.