The goal of this study is to evaluate the safety, pharmacokinetic (PK) characteristics, and preliminary efficacy of a new oral chemical drug in : adults aged 18-70 years (male or female) with moderate to severe active rheumatoid arthritis (RA), who have had inadequate response to or intolerance of at least one conventional synthetic disease-modifying antirheumatic drug (csDMARDs) .
Participants will take the assigned study drug (either tollB-001 Tablets or placebo) once daily orally for 4 weeks, follow up for 1 week.
Aged 18 to 70 years (inclusive) at the time of signing the informed consent form, regardless of gender.
Diagnosis of RA according to the 1987 American College of Rheumatology (ACR) criteria or the 2010 ACR/European League Against Rheumatism (EULAR) classification criteria.
DAS28-CRP > 3.2 at screening (joints that have undergone major surgical treatment or intra-articular injection of glucocorticoids or hyaluronic acid within 6 weeks before randomization are not counted in the TJC and SJC counts).
C-reactive protein (CRP)/high-sensitivity C-reactive protein (hsCRP) ≥ upper limit of normal (ULN) at screening.
Hypersensitivity to the study drug or any of its components.
ACR functional class IV or being bedridden/wheelchair-bound for a long time.
Positive hepatitis B surface antigen (HBsAg); or positive hepatitis B core antibody (HBcAb) with HBV DNA above the lower limit of detection; positive hepatitis C virus (HCV) antibody with positive HCV-RNA; positive human immunodeficiency virus (HIV) antibody or positive syphilis antibody.
Drug or alcohol abuse or dependence at screening, or history of drug or alcohol abuse or dependence within 6 months before randomization.