Evaluation of Ventilation Defects Downstream of Mucus Plugs in Patients With Severe Asthma

Eligibility Criteria

• * Adequate completion of informed consent process with written documentation
• * Patients 18 - 65 years old
• * Physician diagnosis of asthma for \> 1 year
• * Able to perform reproducible spirometry according to ATS criteria based on clinical PFTs.
• * Blood eosinophil count \> 300 cells/μL and FeNO \>25ppb
• * Smoking history \<10 pack years
• * No smoking history (including vapes, cigar, or marijuana use) in the last 3 months
• * Approved for asthma therapy with either dupilumab, tezepelumab, or benralizumab as part of their standard of care
• * Respiratory tract infection within the 4 weeks prior to Visit 1
• * Body mass index (BMI) \> 30 at Visit 1
• * One-time doses such as intra-articular injections require a 4-week washout prior to Visit 1
• * Asthma-related ER visit within the previous 4 weeks of Visit 1
• * Significant concomitant medical illness, including (but not limited to) heart disease, cancer, uncontrolled diabetes, other chronic lung diseases (determined by the Investigator.)
• * Resting O2 saturation \<90% with maximum supplemental O2 delivered by nasal canula
• * Positive urine pregnancy test at Visit 1 or at any time while on the study
• * Participation in an intervention study (including bronchoscopy) or use of investigative drugs within the past 30 days or plans to enroll in such a trial during the study
• * Unable or unlikely to complete study assessments in the opinion of the Investigator
• * Study intervention poses undue risk to patient in the opinion of the Investigator
• * Conditions that will prohibit MRI scanning determined by the MRI safety screening.