Is Fereheme (ferumoxytol) intravenous iron therapy medically indicated for a 24-year-old female with severe iron deficiency anemia, given her low hemoglobin (Hgb) and hematocrit (Hct) levels, and previous unsuccessful oral iron therapy?

Fereheme (Ferumoxytol) is Medically Indicated for This Patient

This 24-year-old female with severe iron deficiency anemia (Hgb 6.9 g/dL, TSAT 10%, serum iron 28 mcg/dL) meets clear criteria for intravenous iron therapy and the requested Fereheme regimen (2 doses of 510 mg IV) is both FDA-approved and medically necessary for her condition. 1

Patient Meets All Criteria for IV Iron Therapy

This patient satisfies the established indications for intravenous iron replacement:

• Age requirement: At 24 years old, she meets the policy criterion of being 18 years or older 1
• Documented iron deficiency anemia: Her laboratory values confirm severe IDA with Hgb 6.9 g/dL (well below the 12 g/dL threshold for women), TSAT 10% (significantly below 20%), and serum iron 28 mcg/dL 2
• Severity of anemia: Her hemoglobin of 6.9 g/dL represents severe anemia requiring urgent intervention, as this level is associated with significant morbidity risk 2

Evidence Supporting IV Iron Over Oral Iron in This Case

Intravenous iron is superior to oral iron for patients with severe anemia (Hgb <10 g/dL), producing significantly greater hemoglobin responses and faster correction of iron deficiency. 2

The guidelines are explicit about when IV iron should be first-line therapy:

• Severe anemia (Hgb <10 g/dL): IV iron is indicated as first-line treatment when hemoglobin is below 100 g/L (10 g/dL), which this patient clearly meets at 6.9 g/dL 2
• Rapid response needed: With hemoglobin this critically low, the faster response time of IV iron (typically 1-2 weeks versus 4-8 weeks for oral iron) is clinically important for reducing morbidity 3, 4
• Higher efficacy: Meta-analyses demonstrate IV iron produces significantly greater hemoglobin increments and ferritin increases compared to oral iron in patients with IDA 2

Fereheme Dosing and Administration is Appropriate

The requested regimen of 2 doses of 510 mg IV once per week aligns precisely with FDA-approved dosing:

• Standard dosing: Fereheme is FDA-approved at 510 mg initially, followed by a second 510 mg dose 3-8 days later 1
• Administration: Each dose should be given as an IV infusion over at least 15 minutes in 50-200 mL of normal saline or 5% dextrose 1
• Total iron replacement: The 1,020 mg total dose (2 × 510 mg) is appropriate for correcting her iron deficit based on her low hemoglobin and body weight 2

Clinical Efficacy Data for Fereheme

Ferumoxytol demonstrates superior efficacy in treating severe IDA, with 81.1% of patients achieving hemoglobin increases ≥2.0 g/dL at Week 5 compared to 5.5% with placebo. 4

Key efficacy outcomes from clinical trials:

• Hemoglobin response: Mean hemoglobin increase of 2.7 g/dL at Week 5 in patients with IDA who failed or could not tolerate oral iron 4
• Rapid onset: Significant hemoglobin improvements occur within 1-2 weeks of treatment 1
• Iron parameter correction: Substantial increases in TSAT and ferritin levels, with mean TSAT increases of 9.2-9.8% and ferritin increases of 300-381 ng/mL by Day 35 1

Safety Considerations and Monitoring

While Fereheme carries a boxed warning for hypersensitivity reactions, the risk is low when proper precautions are followed:

• Hypersensitivity risk: Fatal and serious reactions including anaphylaxis can occur, requiring administration only when personnel and therapies for treating anaphylaxis are immediately available 1
• Infusion protocol: Must be given over at least 15 minutes with the patient in a reclined or semi-reclined position, with monitoring of blood pressure and pulse during and for at least 30 minutes after infusion 1
• Comparative safety: In a large trial of nearly 2,000 patients, moderate-to-severe hypersensitivity reactions occurred in only 0.6% of Fereheme-treated patients 1
• Contraindications: The patient should be screened for history of hypersensitivity to Fereheme or any IV iron product, which would be an absolute contraindication 1

Response Monitoring and Follow-Up

Hematologic response (hemoglobin, ferritin, iron, and transferrin saturation) should be evaluated at least one month following the second Fereheme infusion. 1

Expected response parameters:

• Hemoglobin: Anticipate increase of 1.0-2.7 g/dL by Week 5, with goal of reaching ≥12 g/dL 1, 4
• Iron parameters: TSAT should increase above 20% and ferritin should rise to at least 100 ng/mL 2
• Retreatment criteria: If iron deficiency recurs (ferritin <100 ng/mL or hemoglobin drops below 12 g/dL), the Fereheme dose may be readministered 1, 2

Common Pitfalls to Avoid

• Delaying IV iron in severe anemia: Do not attempt oral iron first when hemoglobin is this critically low (6.9 g/dL), as the patient requires rapid correction to prevent end-organ damage 2
• Inadequate monitoring: Ensure proper observation during and for 30 minutes after each infusion to detect hypersensitivity reactions early 1
• Premature laboratory testing: Do not check iron parameters within 7 days of the last dose, as results may be inaccurately elevated 2
• Missing underlying causes: While treating the anemia, ensure appropriate workup for the cause of iron deficiency (GI blood loss, menorrhagia, malabsorption) is completed 2