Editorial: post hoc analysis of SONIC trial – authors’ reply

We would like to thank Prof. Fraser for his comments on our work regarding the evaluation of different composite outcome measures and treatment.1, 2 Prof. Fraser has provided some interesting comments on specific items that we would like to discuss further. In order to evaluate the effect of treatment on different measures we researched the data of patients who had the following characteristics: evaluable endoscopies with ulcerations present at baseline, week 26 evaluable endoscopies, and who also had CDAI and CRP values. Only 188 pts fulfilled the set criteria and Prof. Fraser's interpretation is that, even in a trial, it is difficult to rely completely on endoscopy as part of a composite remission parameter. However, we are of the opinion that these data mainly emphasise the importance of having a quality endoscopy confirming objective evidence of inflammation as inclusion criteria for clinical trials. Indeed, in this study, 93 patients did not have ulcerations at baseline and were excluded from the analysis (please see table 2 in Peyrin-Biroulet et al.,3 which summarises the exclusion criteria). We do agree that, as part of the emerging ‘treat to target strategy’, it would be important to assess the endoscopic status of patients over time, and that the use of a biomarker such as calprotectin may be able to reduce the amount of follow-up endoscopies. We also believe that this study further emphasises the concept of a ‘window of opportunity’, when treating patients with early disease may be associated with the best possible outcomes. Finally, although the definition of deep remission is still disputed, it is likely that it should incorporate patient-related outcomes, combined with objective measurements such as endoscopy and/or histology. The authors’ declarations of personal and financial interests are unchanged from those in the original article.2