Effect of thalidomide on clinical remission in children and adolescents with refractory Crohn disease: a randomized clinical trial

IMPORTANCE: Pediatric-onset Crohn disease is more aggressive than adult-onset disease, has high rates of resistance to existing drugs, and can lead to permanent impairments. Few trials have evaluated new drugs for refractory Crohn disease in children. OBJECTIVE: To determine whether thalidomide is effective in inducing remission in refractory pediatric Crohn disease. DESIGN, SETTING, AND PATIENTS: Multicenter, double-blind, placebo-controlled, randomized clinical trial of 56 children with active Crohn disease despite immunosuppressive treatment, conducted August 2008-September 2012 in 6 pediatric tertiary care centers in Italy. INTERVENTIONS: Thalidomide, 1.5 to 2.5 mg/kg per day, or placebo once daily for 8 weeks. In an open-label extension, nonresponders to placebo received thalidomide for an additional 8 weeks. All responders continued to receive thalidomide for an additional minimum 52 weeks. MAIN OUTCOMES AND MEASURES: Primary outcomes were clinical remission at week 8, measured by Pediatric Crohn Disease Activity Index (PCDAI) score and reduction in PCDAI by ≥25% or ≥75% at weeks 4 and 8. Primary outcomes during the open-label follow-up were clinical remission and 75% response. RESULTS: Twenty-eight children were randomized to thalidomide and 26 to placebo. Clinical remission was achieved by significantly more children treated with thalidomide (13/28 [46.4%] vs 3/26 [11.5%]; risk ratio [RR], 4.0 [95% CI, 1.2-12.5]; P = .01; number needed to treat [NNT], 2.86). Responses were not different at 4 weeks, but greater improvement was observed at 8 weeks in the thalidomide group (75% response, 13/28 [46.4%] vs 3/26 [11.5%]; RR, 4.0 [95% CI, 1.2-12.5]; NNT = 2.86; P = .01; and 25% response, 18/28 [64.2%] vs 8/26 [30.8%]; RR, 2.1 [95% CI, 1.1-3.9]; NNT = 2.99; P = .01). Of the nonresponders to placebo who began receiving thalidomide, 11 of 21 (52.4%) subsequently reached remission at week 8 (RR, 4.5 [95% CI, 1.4-14.1]; NNT = 2.45; P = .01). Overall, 31 of 49 children treated with thalidomide (63.3%) achieved clinical remission, and 32 of 49 (65.3%) achieved 75% response. Mean duration of clinical remission in the thalidomide group was 181.1 weeks (95% CI, 144.53-217.76) vs 6.3 weeks (95% CI, 3.51-9.15) in the placebo group (P < .001). Cumulative incidence of severe adverse events was 2.1 per 1000 patient-weeks, with peripheral neuropathy the most frequent severe adverse event. CONCLUSIONS AND RELEVANCE: In children and adolescents with refractory Crohn disease, thalidomide compared with placebo resulted in improved clinical remission at 8 weeks of treatment and longer-term maintenance of remission in an open-label follow-up. These findings require replication to definitively determine clinical utility of this treatment.