Fifty-five children (age, 13 ± 2 years) were randomized to treatment with 6-MP (1.5 mg/kg/day) or placebo within 8 weeks of initial diagnosis.
Both groups also received prednisone (40 mg/day) with dosage adjustments based on a defined schedule determined by the change in a patient's disease activity score. Steroid administration was discontinued as remission was achieved. The study continued for 18 months.
In the 6-MP group, the duration of steroid use was shorter (P < 0.001) and the cumulative steroid dose lower at 6, 12, and 18 months (P < 0.01).
9% of the remitters in the 6-MP group relapsed, compared with 47% of controls.
Although remission was induced in 89% of both groups, only 9% of the remitters in the 6-MP group relapsed compared with 47% of controls (P = 0.007).
Growth was comparable in both groups. No clinically significant adverse events occurred, although mild leukopenia and increases in aminotransferase activity were noted in the 6-MP group.
James Markowitz concluded on behalf of the team, "6-MP should be part of the initial treatment regimen for children with newly diagnosed moderate-to-severe CD."