The Role of Cyclosporine in the Treatment of Severe Ulcerative Colitis in the Pediatric Population: A Narrative Review Exploring Known Strategies and New Possibilities.

Cyclosporine is a selective calcineurin inhibitor used, among other areas, in pediatric gastroenterology as rescue therapy in the treatment of severe ulcerative colitis (ASUC-acute severe ulcerative colitis) in children. The introduction of systemic glucocorticosteroids (GCSs) has significantly reduced mortality in ASUC. However, it should be emphasized that long-term use of these drugs is limited due to the high risk of adverse effects observed during therapy and their limited efficacy. The role of cyclosporine as a second-line therapy is referred to as a 'rescue therapy,' which aims to alleviate the symptoms of ASUC, often avoiding life-threatening complications (including toxic megacolon) and postponing the need for urgent colectomy. If colectomy is necessary, this provides time to better prepare the patient nutritionally and psychologically for surgery and to await the effect of slower-acting thiopurine preparations or other chronic treatments; their effectiveness in achieving long-term clinical and endoscopic remission is limited. New therapeutic approaches include cyclosporine as an inducer, which acts as a bridge to new forms of therapy, such as biological drugs, which are used as maintenance preparations in patients. In pediatric patients, there is limited research in the literature on new strategies for the use of cyclosporine. The aim of this review is to assess current evidence on cyclosporine as induction or rescue therapy in pediatric ASUC and explore future integration with biologic and biosimilar strategies, emphasizing its evolving role as a bridging agent toward biologics and novel targeted therapies.