Iron Repletion in Cystic Fibrosis

Prior treatment

• Treated with IV repletion within 3 months of Screening Visit
• Treated with PO repletion within 1 months of Screening Visit
• Treated with red blood cell (RBC) transfusion within 3 months of Screening Visit
• Prior solid organ or hematologic transplant
• Pregnant, or within 3 months of a prior pregnancy at Screening Visit

Other illness

• Known allergy to either IV or PO iron for ID Cohort, or known allergy to PO iron for Borderline ID Cohort
• Presence of a condition or abnormality that in the opinion of the Investigator would compromise the safety of the patient or the quality of the data

Lab values

• Hemodialysis dependent within 6 months of Screening Visit, active use of erythropoiesis stimulating agent at time of Screening Visit, or Glomerular Filtration Rate (GFR) \< 45 estimated based on creatinine (CKD-EPI 2021) at time of Screening Visit

Other

• Use of extracorporeal organ support (ECOS) of any type, including but not limited to extracorporeal membrane oxygenation (ECMO), within 6 months of Screening Visit
• Presence of known cause of anemia other than ID that has required treatment within 12 months of Screening Visit

• A CF diagnosis as evidenced by one or more clinical features consistent with the CF phenotype and at least one of the following criteria:
  • sweat chloride ≥ 60 milliequivalent/liter by quantitative pilocarpine iontophoresis test (QPIT)
  • two well-characterized mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene
  • abnormal nasal potential difference (NPD, change in NPD in response to a low chloride solution and isoproterenol of less than -5 mV)
• Ability to provide written informed consent and to comply with the requirements of the study
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  • Additional Inclusion Criteria for ID Cohort:
• ID defined by at least one of the following criteria:
  • Both of the following: i. transferrin saturation (TSAT) \< 20% OR ferritin \< 30 ug/L ii. hemoglobin \< 12.0 g/dL in female OR hemoglobin \< 13.0 g/dL in male per World Health Organization (WHO) anemia definition b. TSAT \< 15% or ferritin \< 15 ug/L irrespective of hemoglobin value
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  • Additional Inclusion Criteria for Borderline ID Cohort:
• Borderline ID defined by both of the following criteria:
  • TSAT \< 20% OR ferritin \< 60 ug/L
  • not meeting ID Cohort criteria above
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