Early intervention with biologic therapy in Crohn´s disease: how early is early?

BACKGROUND: Early biologic therapy within the first 18-24 months after diagnosis is associated with improved clinical outcomes in Crohn's disease [CD]. However, the definition of the best time to initiate biologic therapy remains unclear. We aimed to assess if there is an optimal timing for early biologic therapy initiation. METHODS: This was a multicentre retrospective cohort study including newly diagnosed CD patients who started anti-tumour necrosis factor [TNF] therapy within 24 months from diagnosis. The timing of initiation of biologic therapy was categorised as ≤6, 7-12, 13-18, and 19-24 months. The primary outcome was CD-related complications defined as a composite of progression of Montreal disease behaviour, CD-related hospitalisations, or CD-related intestinal surgeries. Secondary outcomes included clinical, laboratory, endoscopic, and transmural remission. RESULTS: We included 141 patients where 54%, 26%, 11%, and 9% started biologic therapy at ≤6, 7-12, 13-18, and 19-24 months after diagnosis, respectively. A total of 34 patients [24%] reached the primary outcome: 8% had progression of disease behaviour, 15% were hospitalised, and 9% required surgery. There was no difference in the time to a CD-related complication according to the time of initiation of biologic therapy within the first 24 months. Clinical, endoscopic, and transmural remission was achieved in 85%, 50%, and 29%, respectively, but no differences were found according to the time of initiation of biologic therapy. CONCLUSION: Starting anti-TNF therapy within the first 24 months after diagnosis was associated with a low rate of CD-related complications and high rates of clinical and endoscopic remission, although we found no differences with earlier initiation within this window of opportunity.