OBJECTIVE: Based on several experimental results and on a preliminary study, a trial was undertaken to assess the efficacy of adalimumab, a tumor necrosis factor alpha inhibitor, in patients with radicular pain due to lumbar disc herniation. METHODS: A multicenter, double-blind, randomized controlled trial was conducted between May 2005 and December 2007 in Switzerland. Patients with acute (duration of <12 weeks) and severe (Oswestry Disability Index score of >50) radicular leg pain and imaging-confirmed lumbar disc herniation were randomized to receive as adjuvant therapy either 2 subcutaneous injections of adalimumab (40 mg) at 7-day intervals or matching placebo. The primary outcome was the score for leg pain, based on a visual analog scale (0-100 mm), which was recorded every day for 10 days and at 6 weeks and 6 months. RESULTS: Of the 265 patients screened, 61 were enrolled; 31 patients were assigned to receive adalimumab, and 4 patients in the placebo group were lost to followup. Over time, the course of leg pain was more favorable in the adalimumab group than in the placebo group (P = 0.002). However, the effect size was relatively small, and at the last followup visit the difference was 13.8 (95% confidence interval -11.5, 39.0). Compared with patients in the placebo group, approximately twice as many patients in the adalimumab group fulfilled the criteria for "responders" and for "low residual disease impact" (P < 0.05), and fewer surgical discectomies were performed (6 versus 13 in the placebo group; P = 0.04). CONCLUSION: The addition of a short course of adalimumab to the treatment regimen of patients experiencing acute and severe sciatica resulted in a small decrease in leg pain and in significantly fewer surgical procedures.