To be eligible for the study, subjects must meet all of the following criteria:

Age ≥ 18 years old

Physician diagnosis of asthma confirmed through medical record documentation.

Documented history of 12% FEV1 reversibility post-bronchodilator and/or Methacholine PC 20 score of 16mg/ml or less.

Non-smoker for \> 6 months before enrollment into the trial

Less than 5 pack year smoking history defined as the average packs smoked per day multiplied by the years of active smoking.

Willing and able to adhere to the study visit schedule and other protocol-specified procedures.

Ex Vivo Stimulation of Whole Blood as a Means to Determine Glucocorticoid Sensitivity to Mild-to-Moderate and Refractory Asthmatics