Efficacy and safety of modified Bushen Yiqi formulas (MBYF) as an add-on to formoterol and budesonide in the management of COPD: study protocol for a multicentre, double-blind, placebo-controlled, parallel-group, randomized clinical trial: FB-MBYF Trial

BACKGROUND: Inhaled glucocorticoid corticosteroid (ICS), long-acting β2-adrenoceptor agonist (LABA), and other drugs have limited therapeutic effects on COPD with significant individual differences. Traditional Chinese medicine (TCM)-modified Bushen Yiqi formula (MBYF) demonstrates advantages in COPD management in China. This study aims to evaluate the efficacy and safety of MBYF as an add-on to budesonide/formoterol in COPD patients and confirm the related genes affecting the therapeutic effect in the treatment of COPD. METHODS: In this multicentre, randomised, double-blind, placebo-controlled, parallel-group study, eligible patients with COPD will randomly receive a 360-day placebo or MBYF as an adjuvant to budesonide/formoterol in a 1:1 ratio and be followed up with every 2 months. The primary outcomes will be the frequency, times, and severity of acute exacerbation of COPD (AECOPD), COPD assessment test (CAT) score, and pulmonary function tests (PFTs). The secondary outcomes will include the modified Medical Research Council (mMRC) dyspnoea scale, 6-min walking test (6MWT), BODE index, quantitative scores of syndromes classified in TCM, inflammation indices, and hypothalamic-pituitary-adrenaline (HPA) axis function. We will also test the genotype to determine the relationship between drugs and efficacy. All the data will be recorded in case report forms (CRFs) and analysed by SPSS V.20.0. DISCUSSION: A randomized clinical trial design to evaluate the efficacy and safety of MBYF in COPD is described. The results will provide evidence for the combination therapy of modern medicine and TCM medicine, and individual therapy for COPD.Trial registration. TRIAL REGISTRATION: ID: ChiCTR1900026124, Prospective registration. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13063-022-06057-7.