A multicenter, placebo-controlled clinical trial and preliminary experimental study exploring the efficacy of modified Banxia Xiexin Decoction in the treatment of advanced colorectal cancer.

ETHNOPHARMACOLOGICAL RELEVANCE: Recent studies in China have increasingly focused on the evidence-based evaluation of malignant tumors, including colorectal cancer (CRC), leveraging the unique properties of herbal medicine. This has led to notable progress in the development of novel therapies. Clinical observations indicate that the modified Banxia Xiexin Decoction (mBXD) exhibits significant anti-cancer effects. However, well-designed clinical trials and foundational research in this field remain insufficient.

AIMS OF THE STUDY: This study aims to assess the clinical efficacy and safety of mBXD in the treatment of advanced CRC, alongside preliminary in vivo and in vitro verification of its anti-CRC effects.

METHODS: A clinical trial was conducted from October 2020 to October 2024 across 12 hospitals in Southwest China. Eligible participants were randomly assigned to either the mBXD group or the placebo group. Both groups received standard chemotherapy combined with targeted therapy; the mBXD group received mBXD granules (Ready-to-use), while the placebo group received a placebo. Treatment lasted for six months (six cycles). The primary endpoint was progression-free survival (PFS), while secondary endpoints included overall survival (OS), objective response rate (ORR), disease control rate (DCR), and serum tumor markers. Efficacy was assessed every two cycles, with follow-ups conducted every three months after treatment completion until disease progression or death. This study is registered with the Chinese Clinical Trial (No. ChiCTR2100041643). Basic research included the establishment of a subcutaneous CT26 colon cancer model and the use of the HCT116 cell line, with mBXD interventions to monitor tumor growth and evaluate the viability, invasion, and migration of HCT116 cells.

RESULTS: A total of 129 participants were enrolled. Compared to the placebo group, the mBXD group showed a 1.9-month and 2.8-month extension in PFS and OS, respectively, with a 17 % reduction in the risk of disease progression and a 15 % reduction in the risk of death (P = 0.341, 0.465). After two, four, and six cycles, the ORR and DCR in the mBXD group were 3.7-12.6 % and 1.2-18.5 % higher than those in the placebo group, respectively, with only the DCR after six cycles reaching statistical significance (P = 0.037). Moreover, serum levels of CEA and CA724 were significantly reduced in the mBXD group after four and six cycles (P ≤ 0.05). No severe adverse events were reported during the trial. Additionally, mBXD significantly inhibited subcutaneous tumor growth after 14 days of treatment (P < 0.05), and its drug-containing serum notably suppressed the viability, migration, and invasion of HCT116 cells.

CONCLUSIONS: mBXD demonstrates clinical efficacy in prolonging PFS and OS, stabilizing tumor lesions, and reducing serum tumor marker levels in advanced CRC patients. The treatment is both safe and well-tolerated. Furthermore, mBXD significantly inhibits the growth of subcutaneous CT26 colon cancer and suppresses the viability, invasion, and migration of HCT116 cells.