LAUSR

We thank Aksan and colleagues for their interest in our recent article on the budgetary implications of using iron isomaltoside 1000 (IIM) relative to other intravenous (IV) iron formulations in patients with inflammatory bowel disease (IBD) and iron deficiency anemia (IDA) in the Danish setting [1]. We disagree with the key points raised and would counter that, in their letter, the correspondents have selectively quoted from their own study, made incorrect and misleading statements regarding the availability of data on the administration of high doses of IIM, and have, regrettably, demonstrated a misunderstanding of the modeling approaches employed in the analysis. Before responding to the individual points raised, we would note two overarching aspects of the letter that appear to be internally inconsistent. Firstly, there is a great tension between what the correspondents consider to be an acceptably large sample size in different circumstances. On the one hand, they claim that extrapolation of data from 100 anemic patients in the Non-Interventional Monofer (NIMO) study to a Danish IBD population of 3522 patients is not ‘‘meaningful’’ on the grounds that the sample population is too small. On the other hand, they claim that their NMA-based efficacy comparison between IIM and ferric carboxymaltose (FCM) results in the ‘‘unequivocal’’ conclusion that FCM is more effective than IIM, despite (a) the nonsignificance of the findings and (b) IIM being linked into the network using data from just 113 patients on oral iron in a single study [2]. The implicit extrapolation in the latter case would be to all patients, globally, with IBD and IDA requiring IV iron. Maintaining that the network meta-analysis (NMA) results hold true in the global population of patients with IBD and IDA would appear to be completely at odds with the simultaneous dismissal of our assumption that the NIMO study anemic IBD subgroup would be representative of a Danish population of patients with IBD and IDA. Secondly, there appears to be a contradiction between whether the correspondents would prefer the use of data reflecting ‘‘real-world’’ evidence or alignment with the summaries of product characteristics (SPC) or treatment guidelines. This is particularly apparent in the comments on dosing and retreatment frequency, in which the correspondents lament R. F. Pollock (&) Covalence Research Ltd, London, UK e-mail: [email protected]