Preclinical assessment of inhalational subacute safety of nebulized MP-171 (BromAc®)

BromAc^® (MP-171) is a novel first in class therapeutic agent under investigation for its potential in treating respiratory diseases. Evaluating its safety profile following inhalation is necessary for future clinical application. Here, we evaluated BromAc^® safety in an extended subacute short-term inhalation study. Forty BALB/c mice were divided into five groups (N = 8 each): sham control, saline control, and three BromAc^® dose groups at 0.250/20, 0.500/20, and 0.750/20 mg/mL. Treatments were administered by inhalation three times daily for 28 days. A final single dose was given on Day 29 before euthanasia. Various parameters were assessed during the study to evaluate the effect of BromAc such as wellbeing and bodyweight, along with tissue pathology and inflammatory cytokine assessment. The results indicated that inhalation of BromAc^® over 28 days did not affect general health, behavior, or body weight compared to controls. No signs of respiratory distress, hemorrhage, hypoxia, or any other disorders were observed. Mild, non-dose-dependent lung pathology and inflammatory changes were observed across all groups including controls. There was no difference between treated and control groups on multiplex immunoassay. These findings suggest that BromAc^® is safe for inhalation at the tested concentrations and exposure duration.