Background This study aimed to compare efficacy and safety of test-adalimumab (CinnoRA®, CinnaGen, Iran) to the innovator product (Humira®, AbbVie, USA) in adult patients with active rheumatoid arthritis (RA). Methods In this randomized, double-blind, active-controlled, non-inferiority trial, a total of 136 patients with active RA were randomized to receive 40 mg subcutaneous injections of either CinnoRA® or Humira® every other week, while receiving methotrexate (15 mg/week), folic acid (1 mg/day), and prednisolone (7.5 mg/day) over a period of 24 weeks. Physical examinations, vital sign evaluations, and laboratory tests were conducted in patients at baseline and at 12-week and 24-week visits. The primary endpoint in this study was the proportion of patients achieving moderate and good disease activity score in 28 joints-erythrocyte sedimentation rate (DAS28-ESR)-based European League Against Rheumatism (EULAR) response. The secondary endpoints were the proportion of patients achieving American College of Rheumatology (ACR) criteria for 20% (ACR20), 50% (ACR50), and 70% (ACR70) responses along with the disability index of health assessment questionnaire (HAQ), and safety. Results Patients who were randomized to CinnoRA® or Humira® arms had comparable demographic information, laboratory results, and disease characteristics at baseline. The proportion of patients achieving good and moderate EULAR responses in the CinnoRA® group was non-inferior to the Humira® group at 12 and 24 weeks based on both intention-to-treat (ITT) and per-protocol (PP) populations (all p values >0.05). No significant difference was noted in the proportion of patients attaining ACR20, ACR50, and ACR70 responses in the CinnoRA® and Humira® groups (all p values >0.05). Further, the difference in HAQ scores and safety outcome measures between treatment arms was not statistically significant. Conclusion CinnoRA® was shown to be non-inferior to Humira® in terms of efficacy at week 24 with a comparable safety profile to the reference product.