Efficacy and safety of HL301 in the treatment of acute bronchitis and acute exacerbation of chronic bronchitis: a phase 2, randomized, double-blind, placebo-controlled, multicenter study

Abstract

Purpose: The efficacy and safety of Chinese herbs for symptomatic treatment of bronchitis is not well established. We evaluated the efficacy and safety of a combination product of seven herbs (HL301) for the treatment of acute bronchitis (AB) and acute exacerbation of chronic bronchitis (AECB) using a randomized, double-blind, placebo-controlled, multicenter trial design.Methods: A total of 160 patients with AB or with AECB were randomized to receive placebo or one of three doses of HL301 (0.6g/day, 1.2g/day, or 1.8g/day) for a total of 7 days. The primary study endpoint was the change in bronchitis severity score (BSS) from the baseline visit (visit 2) to the end of treatment visit (visit 3). Other efficacy variables were percentage BSS systemic sign efficacy after treatment and change in individual BSS parameters after treatment.Findings: Changes in BSS from visit 2 to visit 3 in the three treatment groups (4.632.24, 4.081.63, and 4.15 +/- 1.74 in the HL301 0.6g/day, 1.2g/day, and 1.8g/day groups, respectively) were higher than that of the placebo group (2.88 +/- 2.57) in the per protocol set (PPS) (P<.05), and it was also valid in the full analysis set (FAS). The number of participants whose symptoms (measured by BSS) improved at least 30% after treatment was higher in all three treatment groups compared to the placebo group in both the FAS and the PPS (P<.05, for all).Implications: Three different doses of HL301 (0.6g/day, 1.2g/day, and 1.8g/day) were effective in decreasing the BSS index compared to placebo. HL301 may be effective for symptomatic treatment of both AB and AECB.Limitations: Essential components of HL301 have not been delineated in the study and patients with AB and AECB were indiscriminately enrolled in the present study. Respective evaluation of the efficacy of HL301 for AB and AECB will be necessary in the future.