A Study to Assess the Effect of Dexpramipexole in Adolescents and Adults With Severe Eosinophilic Asthma.

Exclusion Criteria

• •Asthma-related criteria
• •1. A participant who experiences a severe asthma exacerbation (defined as a deterioration of asthma that results in emergency treatment, hospitalization due to asthma, or treatment with systemic corticosteroids) at any time from 4 weeks prior to Screening Visit.
• •Participants who experience an asthma exacerbation during the Screening/Run-in Period may remain in screening and proceed with study visits 14 days after they have completed their course of oral steroids or returned to their pre-Screening Visit maintenance dose of oral steroids and the investigator considers participant has returned to baseline status.
• •2. Current diagnosis of diseases which may confound interpretation of this study's findings such as allergic bronchopulmonary aspergillosis, eosinophilic granulomatosis with polyangiitis, eosinophilic gastrointestinal diseases, hypereosinophilic syndrome, chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis.
• •3. Respiratory infection: Upper or lower respiratory tract, sinus, or middle ear infection within the 4 weeks before Screening Visit 1.
• •4. For participants aged 12 to 17 years old, AEC of \<0.15x10⁹/L at Screening Visit 1.
• •Prohibited medications/procedures
• •5. Treatment with a biologic investigational drug in the last 5 months prior to Screening Visit 1. Treatment with non-biologic investigational drugs in the previous 30 days or five-half-lives prior to Screening Visit 1, whichever is longer. Treatment with GSK3511294 (long-acting anti-IL-5) in the past 12 months.
• •6. Treatment with any of the following monoclonal antibody therapies within 120 days prior to Baseline Visit: benralizumab, dupilumab, mepolizumab, reslizumab, omalizumab, tezepelumab, or tralokinumab.
• •7. Treatment with pramipexole (Mirapex®) within 30 days of Baseline Visit.
• •8. Treatment with selected drugs known to have a substantial risk of neutropenia in the past 30 days prior to Screening Visit 1.
• •9. Bronchial thermoplasty procedure in the past 12 months prior to Screening Visit 1 or planned during the coming year.
• •General medical history
• •10. Weight \<40 kg at Screening Visit 2.
• •11. Current smoking within the 12 months prior to Screening Visit 1 or a smoking history of \>10 pack-years. Smoking includes tobacco, vaping, and/or marijuana use.
• •12. Known or suspected alcohol or drug abuse
• •13. Uncontrolled severe hypertension: systolic blood pressure \>180 mmHg or diastolic blood pressure \>110 mmHg prior to the Baseline Visit despite antihypertensive therapy.
• •14. History of malignancy that required surgery (excluding local and wide-local excision), radiation therapy and/or systemic therapy during the 5 years prior to the Baseline Visit.
• •15. History of human immunodeficiency virus (HIV) infection or chronic infection with hepatitis B or C.
• •16. A helminth parasitic infection diagnosed within 24 weeks prior to Screening Visit 1 that has not been treated with or has failed to respond to standard of care (SoC) therapy.
• •17. Medical or other condition likely to interfere with participant's ability to undergo study procedures, adhere to visit schedule, or comply with study requirements.
• •18. Known or suspected noncompliance with medication.
• •19. Unwillingness or inability to follow the procedures outlined in the protocol.
• •Clinical safety labs
• •20. Absolute neutrophil count (ANC) \<2.000x10⁹/L at Screening Visit 1 or Screening Visit 2.
• •21. Renal dysfunction, defined as an estimated glomerular filtration rate (eGFR) \<60 mL/min/1.73m² at Screening Visit 2 (using the Chronic Kidney Disease Epidemiology Collaboration \[CKD-EPI\] formula for age ≥18 years at screening; using the Bedside Schwartz eGFR formula).
• •22. Active liver disease defined as any known current infectious, neoplastic, or metabolic pathology of the liver or unexplained elevations in alanine aminotransferase (ALT), aspartate aminotransferase (AST), \>3x the upper limit of normal (ULN), or total bilirubin \>2x ULN at Screening Visit 2 confirmed by a repeat abnormal measurement of the relevant value(s), at least 1 week apart.
• •Cardiac safety
• •23. History of New York Heart Association class IV heart failure or last known left ventricular ejection fraction \<25%.
• •24. History of major adverse cardiovascular event (MACE) within 3 months prior to the Baseline Visit.
• •25. History of cardiac arrhythmia within 3 months prior to the Baseline Visit that is not controlled by medication or via ablation.
• •26. History of long QT syndrome.
• •27. Corrected QT interval by Fridericia (QTcF) interval \>450 ms for males and \>470 ms for females at Screening Visit 2 or QTcF ≥480 ms for participants with bundle branch block.
• •28. Clinically important abnormalities in resting ECG that may interfere with the interpretation of QTcF interval changes at Screening Visit 2, including heart rate \<45 beats per minute (bpm) or \>100 bpm.
• •Pregnancy/Lactation
• •29. Pregnant women or women breastfeeding
• •30. Males who are unwilling to use an acceptable method of birth control during the entire study period (ie, condom with spermicide).