Effect of OM-85 BV on reducing bronchiectasis exacerbation in Chinese patients: the iPROBE study

Background: Bronchiectasis is characterized by recurrent infectious exacerbations. No existing data inform preventive strategy for exacerbations beyond chronic macrolides. OM-85 BV, an immunostimulant, has been shown to prevent recurrent respiratory infections. We initiated this 1-year, multi-centered, double-blind, and controlled trial to investigate the PReventive effect of OM-85 BV on Bronchiectasis Exacerbations in Chinese patients (iPROBE). Methods: Patients with bronchiectasis aged 18 to 75 years, having at least one exacerbation in the past year, were randomized to receive, in addition to any respiratory medications, two courses of 7 mg of OM-85 BV or matching placebo (one capsule orally per day for 10 days a month) for 3 consecutive months, followed by 3 months without treatment. The primary outcomes included the number of acute infectious exacerbations and the time to first exacerbation. Secondary endpoints included patient-reported respiratory outcomes. Safety measures were also assessed. Results: Among the 196 participants, 99 were in the OM-85 BV group and 97 in the placebo group. At week 52, the mean number of acute exacerbations per patient was equal to 0.98 and 0.75, respectively, in the two groups (P=0.14). Difference in the time to first pulmonary exacerbation was not statistically significant (P=0.11). There was no statistically significant difference in any secondary end-points. The safety profile in the two arms was good and the majority of adverse events were mild. Conclusions: OM-85 BV did not demonstrate protection in decreasing pulmonary exacerbations of bronchiectasis in this trial performed in Chinese patients. It had good safety profile.