Efficacy and safety of bacterial lysate OM-85 in the treatment of uncomplicated acute respiratory infections: a double-blind, placebo-controlled, multicenter, randomized trial

Abstract

Aim. To evaluate the efficacy and safety of OM-85 in the treatment of uncomplicated acute respiratory infections (ARI) in adults. Materials and methods. A double-blind, placebo-controlled, multicenter, randomized trial included 556 patients (18–60 years old) with mild and moderate ARI and negative results of polymerase chain reaction analysis for SARS-CoV-2 RNA and rapid test for influenza A and B viruses. Patients were randomized into two groups: in the first group (n=278), patients received OM-85 (Broncho-munal®) one capsule 7 mg/day for 10 days, while the second group (n=278) was treated with placebo in the same regimen. The primary endpoint was the dynamics of the severity of symptoms over 3, 5, 7 and 10 days of treatment according to the 21-item Wisconsin Upper Respiratory Symptom Survey (WURSS-21), which was assessed by the area under the curve. Secondary efficacy criteria were the dynamics of the severity of symptoms according to the Common Cold Questionnaire (CCQ), the time to the resolution of symptoms according to WURSS-21 and CCQ, the proportion of patients with body temperature below 37°C on each day of treatment, frequency of the need for systemic antibacterial therapy. Results. The superiority of OM-85 over placebo by primary endpoint was observed on the 5th, 7th and 10th days of treatment. OM-85 efficacy has also been proven by secondary criteria. OM-85 shortened the time until the symptoms of ARI resolved according to the WURSS-21 and CCQ, increased the proportion of patients with body temperature below 37°C by 2–9 days. The time needed to resolve the symptoms of disease in 20% of patients according to WURSS-21 was 7 and 9 days in patients taking OM-85 and placebo, respectively. Bacterial lysate increased the probability of complete disappearance of symptoms according to CCQ by 45.7% compared to placebo. The analysis of the frequency and severity of adverse events, laboratory tests, physical and instrumental examination results during treatment confirmed the good tolerability and safety of OM-85. Conclusion. The study confirmed the efficacy and safety of OM-85 in the complex treatment of ARI in adults.