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.