P435. Intravenous iron need to maintain stable haemoglobin - an open-label, 1 year extension study of iron isomaltoside 1000 in subjects with inflammatory bowel disease
W. Reinisch, on behalf of the study group, Medical University Hospital, Department of Internal Medicine III, Vienna, Austria
Intravenous (IV) iron is an established treatment for subjects with inflammatory bowel disease (IBD) and iron deficiency anaemia. The need for repetitive IV iron necessary to safely maintain once established stable haemoglobin (Hb) over time is not well examined.
Iron isomaltoside 1000 (Monofer®) is a new high dose IV iron, which in a recent 8 weeks study in IBD subjects demonstrated good tolerability and efficacy comparable to other IV irons (Reinisch et al., Am J Gastro, 2013). The present study is an extension to this study, which evaluates the need for additional high single IV iron doses to prevent anaemia and maintain a stable Hb ≥12.0 g/dL (ClinicalTrial.gov: NCT01410435).
This was a prospective, open-label, 12 months study (P-IBD-01-ext) of European IBD subjects willing to participate after completing the lead-in study. Subjects were allowed re-dosing with 500–2000 mg single doses of iron isomaltoside 1000 infused over 15 min at 3 months intervals depending on a predefined algorithm based upon Hb, transferrin saturation (TfS), and s-ferritin levels. Outcome measures included Hb, iron related biochemistry, safety parameters, and need for additional iron dosing.
39 subjects were enrolled of which 35 were included in the full analysis set. The mean (SD) Hb was 12.3 (1.5) g/dL at baseline, 12.8 (1.6) g/dL at 3 months, 12.8 (1.6) g/dL at 6 months, 12.9 (1.4) g/dL at 9 months, and 12.9 (1.6) g/dL at 12 months. There was a significant increase in s-ferritin (p < 0.0001) and TfS (p = 0.0003) from baseline to 12 months.
Thirty-four subjects required re-dosing, and the mean cumulative dose was 2192 mg. The mean single dose at different visits was: Baseline: 1167 mg, 3 months: 1002 mg, 6 months: 1154 mg, 9 months: 1000 mg. 69 single doses were infused as 14 subjects were re-dosed once, 11 were re-dosed twice, 3 were re-dosed thrice, and 6 were re-dosed four times.
Twenty-three subjects had a Hb ≥12.0 g/dL at baseline and of these, 21 subjects were re-dosed at least once (mean dose number: 1.6, mean cumulative dose: 1714 mg). By using last observation carried forward, 17 out of these 23 (74%) subjects were able to maintain Hb ≥12.0 g/dL.
Non-serious probably related hypersensitivity reactions without significant hypotension were reported at the beginning of the infusion in 2 patients, who recovered without sequelae.
Iron isomaltoside 1000 administered repeatedly in high single doses up to 2000 mg in 15 min was efficacious and resulted in Hb ≥12.0 g/dL in the majority of subjects. Rapid infusions of high dose iron isomaltoside 1000 were completed without major safety issues.
The study was sponsored by Pharmacosmos A/S.