Safety, Tolerability, and Pharmacokinetics of Oral Ferric Maltol in Children With Iron Deficiency: Phase 1 Study.

Iron deficiency is common in children and can have negative effects on behavior and function. Standard oral ferrous iron replacement is poorly absorbed and can cause treatment-limiting gastrointestinal adverse events (AEs). Ferric maltol is formulated to improve gastrointestinal absorption and tolerability versus oral ferrous compounds. In adult phase 3 trials, it increased hemoglobin and iron stores versus placebo, with a gastrointestinal AE profile similar to placebo. Here, we assess different doses of ferric maltol in children with iron deficiency. Methods: This phase 1 trial involved children of age 10 to 17 years with ferritin <30 µg/L (or <50 µg/L with transferrin saturation [TSAT] <20%). Children were randomized 1:1:1 to oral ferric maltol 7.8 mg, 16.6 mg, or 30 mg twice daily for 9 days and once on day 10. The primary outcomes were iron uptake measures (serum iron and TSAT) and population pharmacokinetic analyses. Results: The trial included 37 children (mean age 14.0 years; baseline mean ± standard deviation ferritin 16.3 ± 8.02 µg/L). Ferric maltol increased iron uptake nondose-proportionally: serum iron and TSAT plateaued between the 2 higher doses on day 1 and were comparable across all doses on day 10. Twenty children (54%) experienced AEs (all mild/moderate, gastrointestinal 32%), with similar frequencies in each group. Conclusions: All 3 ferric maltol doses increased iron uptake in children with iron deficiency, even over the short study duration, and were well tolerated. Nondose-dependent changes in serum iron and TSAT indicate physiologic regulation of iron uptake to meet the body's needs.