CT to Assess the Efficacy and Safety of Adding GMA to Infliximab in Paediatric Patients With Steroid-refractory Ulcerative Colitis

The primary endpoint will be evaluated through the following variables: PUCAI score, IFX levels, and steroid treatment. Clinical response to IFX will be evaluated through the PUCAI score. The response will be considered clinically significant if PUCAI points continue maintained below 30 during the study period. The IFX response will also be determined by IFX serum levels. A therapeutic IFX level, i.e. for achieving an adequate clinical response, is established above 6 μg/mL. Finally, the necessity, or not, of a steroid treatment during the study period will also be indicative of successful efficacy with GMA.