Ferric Maltol Is Effective in Correcting Iron Deficiency Anemia in Patients with Inflammatory Bowel Disease: Results from a Phase-3 Clinical Trial Program

Phase 3 randomized, double-blind, placebo-controlled trial in adults with ulcerative colitis or Crohn's disease in remission or with mild-to-moderate disease activity and mild-to-moderate iron deficiency anemia. Participants had previously failed to respond to, or were intolerant of, oral ferrous iron; for the ferric maltol group, 64 were randomized and 55 completed the study.

Oral ferric maltol capsules were given at 231.5 mg per capsule, equivalent to 30 mg elemental iron, twice daily in the morning and at night on an empty stomach with water for 12 weeks. The active regimen was compared with placebo in a double-blind design.

Ferric maltol improved hemoglobin more than placebo and was generally well tolerated. In the ferric maltol group, mean hemoglobin increased from 11.00 to 13.20 g/dL by week 12, compared with 11.10 to 11.20 g/dL with placebo, and the primary endpoint difference was significant (P < 0.0001). The adjusted mean treatment difference versus placebo was 1.04 g/dL at week 4 and 1.73 g/dL at week 8; the odds ratio for hemoglobin increases of at least 1 g/dL was 41.8 (95% CI, 13.5-129.9), and the odds ratio for hemoglobin normalization was 15.3 (95% CI, 5.9-39.3). Median time to hemoglobin normalization among evaluable ferric maltol-treated patients was 57 days. Adverse events, including gastrointestinal events and serious adverse events, were broadly similar to placebo, and inflammatory bowel disease activity was not worsened.

The treatment period was short at 12 weeks, so longer-term efficacy and safety were not established. The active arm was relatively small, and the population was limited to patients with mild-to-moderate anemia and quiescent or mildly active inflammatory bowel disease with prior oral iron intolerance or nonresponse, which may limit generalizability. The trial also does not establish comparative effectiveness versus intravenous iron.