The Phase 2 EXHALE-1 clinical trial, initiated by clinical-stage biotechnology company Areteia Therapeutics, Inc. (“Areteia”), sought to understand how safe, effective, and well-tolerated dexpramipexole was in reducing symptoms of eosinophilic asthma. Eosinophilic asthma is a severe subtype of asthma characterized by high levels of eosinophils (a type of white blood cell) in the blood, mucus, and lung tissues. Eosinophils can prompt inflammation. People with eosinophilic asthma are prone to wheezing, coughing, chest pressure, nasal polyps, and difficulty breathing. Biologics and corticosteroids can help manage symptoms. But many people still struggle to control their symptoms even on current medications, leading to a need for improved treatment options.
Areteia shared that results from the study were recently published in the Journal of Allergy and Clinical Immunology.
Evaluating an Eosinophilic Asthma Therapy
Altogether, 103 participants with poorly controlled eosinophilic asthma enrolled in the EXHALE-1 trial. Participants were split into four groups. The first group received 37.5mg dexpramipexole twice daily, the second 75mg twice daily, the third 150mg twice daily, and the fourth a placebo. Researchers wanted to identify whether dexpramipexole, an investigational orally-bioavailable synthetic amino-benzothiazole, was effective in reducing absolute eosinophil counts. At the start of the study, the enrolled participants had absolute eosinophil counts at greater than or equal to 300/μL.
Dexpramipexole was effective across all treatment groups, with particularly efficacy in the 75 and 150mg groups. By week 12, dexpramipexole reduced eosinophil counts by 66% and 77% respectively. In these same groups, the treatment reduced biomarkers of inflammation and showed lung function improvements. Dexpramipexole was also safe and well-tolerated by participants. Most adverse reactions were mild-to-moderate. These included anaphylaxis, back pain, neutropenia (low neutrophil count), and recurrent sinusitis. Only one person discontinued treatment due to an adverse reaction, which they reported to be arm pain.
Ultimately, the researchers determined that dexpramipexole showed similar effiacy to available IL-5 biologics like mepolizumab that aim to reduce eosinophil levels.
