Effectiveness of Yishen Tongbi decoction versus methotrexate in patients with active rheumatoid arthritis: A double-blind, randomized, controlled, non-inferiority trial

BACKGROUND: Yishen Tongbi decoction (YSTB) which is an herbal formula, has been used for the treatment of rheumatoid arthritis (RA) for more than ten years with a better curative effect. Methotrexate (MTX) is an effective anchoring agent used to treat rheumatoid arthritis. There were, however, no head-to-head comparative randomized controlled trials comparing traditional Chinese medicine (TCM) to MTX, Therefore, we performed this double-blind, double-model, randomized controlled trial of the efficacy and safety of YSTB and MTX in the treatment of active RA for 24 weeks. METHODS: Patients who met the enrollment criteria were randomly selected (1:1) to receive either YSTB therapy (YSTB 150 ml once daily + MTX placebo 7.5-15 mg once weekly) or MTX therapy (MTX 7.5-15 mg once weekly + YSTB placebo 150 ml once daily) in treatment cycles lasting 24 weeks. The percentage of patients who achieve a clinical disease activity index (CDAI) response at week 24 is the primary efficacy outcome. A 10% risk differential non-inferiority margin was previously defined. The Chinese Clinical Trials Registry has recorded this trial (ChiCTR-1,900,024,902, registered on August 3rd 2019, http://www.chictr.org.cn/index.aspx). RESULTS: Out of 118 patients whose eligibility was determined from September 2019 to May 2022, 100 patients (n = 50 for each group) were enrolled in the research overall. The 24-week trial was completed by 82% (40/49) of the YSTB group's patients and 86% (42/49) of the MTX group's patients. In the intention-to-treat analysis, 67.4% (33/49) of patients in the YSTB group met the main outcome of CDAI response criteria at week 24, compared to 57.1% (28/49) in the MTX group. The risk difference was 0.102 (95% CI -0.089 to 0.293), which demonstrated the non-inferiority of YSTB to MTX. After further testing for superiority, the ratio of CDAI responses achieved by the YSTB and MTX groups was not statistically significant (p = 0.298). At the same time, in week 24, secondary outcomes such as the ACR 20/50/70 response, the European Alliance of Associations for Rheumatology good or moderate response, remission rate, simplified disease activity index response, and low disease activity rate all showed similar statistically significant patterns. There was statistically significant attainment of ACR20 (p = 0.008) and EULAR good or moderate response (p = 0.009) in two groups at week 4. The intention-to-treat analysis results and the per-protocol analysis results were in agreement. The incidence of drug-related adverse events was not statistically different between the two groups (p = 0.487). CONCLUSIONS: Previous studies have used TCM as an adjunct to conventional therapy, and few of them have directly compared it with MTX. In order to lessen disease activity in RA patients, this trial demonstrated that YSTB compound monotherapy was non-inferior to MTX monotherapy and had superior efficacy following short-term treatment. This study provided evidence-based medicine in the treatment of RA with compound prescriptions of TCM and contributed to promoting phytomedicine use in RA patients.