Methotrexate for Primary Maintenance Therapy in Mild-to-Moderate Crohn Disease in Children.

Objectives: Despite limited data, methotrexate (MTX) is often used as primary maintenance therapy in pediatric Crohn disease (CD). We sought to assess the effectiveness of MTX as "initial" primary maintenance therapy in newly diagnosed mild/moderate pediatric CD and ascertain baseline predictive factors.

Methods: Single-center 10-year retrospective review of newly diagnosed CD patients treated with MTX as primary maintenance therapy. We compared baseline characteristics of those patients with sustained response/clinical remission to those patients who escalated to anti-TNF therapy within 1 year. Pediatric Crohn Disease Activity Index (PCDAI) ≤ 10 defined remission.

Results: We identified 65 patients (mean age, 11.8 years; 72 % male; mean ± SD PCDAI, 17.8 ± 10.5) who started MTX ≤4 months of diagnosis as their primary maintenance therapy. Initial therapy prior to MTX was corticosteroids (CS) (54/65), defined diet (4/65), and combination CS/diet (6/65). Oral dosing was used in 55%; mean dose was 11.4 mg/m 2 orally and 12.5 mg/m 2 subcutaneously. At 1 year, 36 of 65 (55%) were on MTX monotherapy, and of those, 32 of 36 were in clinical remission; 81% were in steroid-free remission for the year following induction. For the 36 patients on MTX at 1 year, 14 (39%) had gross mucosal healing (22% of the original cohort). Ten additional patients had mucosal improvement (37% of total healed/improved). Fifteen patients (23%) were early failures, transitioning to anti-TNF ≤4 months. Baseline PCDAI, hemoglobin, ESR, albumin, and route of administration were not predictive of outcome. MTX was well tolerated in our cohort, with only 1 patient stopping due to elevated aminotransferases. No patient required CD surgery in the 1-year follow-up.

Conclusions: MTX may have a primary maintenance role in mild/moderate CD.