Is administration of Fereheme (ferumoxytol) 510 mg, intravenous (IV), once per week for 2 weeks, medically necessary for treatment of a 24-year-old female with iron deficiency anemia, who has an unsatisfactory response to oral iron therapy and meets criteria with lab results from 2023 showing low transferrin saturation (TSAT) and elevated transferrin levels?

Medical Necessity Assessment for Feraheme (Ferumoxytol) Administration

Direct Recommendation

The request for Feraheme (ferumoxytol) 510 mg IV x 2 treatments is NOT medically necessary at this time due to outdated laboratory values from 2023. Current iron studies must be obtained to confirm ongoing iron deficiency anemia before proceeding with IV iron therapy.

Rationale and Clinical Criteria

Laboratory Requirements for IV Iron Therapy

The patient's qualifying labs from April 2023 are too old to justify current treatment authorization. Iron deficiency anemia (IDA) is defined as TSAT <20% or ferritin <30 ng/mL for non-CKD patients 1. While the patient's 2023 labs (TSAT 10%, transferrin 183) clearly met criteria at that time, iron status can change significantly over months, particularly in a 24-year-old female with potential ongoing menstrual losses 1.

Critical Clinical Considerations

Recent laboratory values are essential because:

• Iron stores can fluctuate substantially over time, especially in premenopausal women with variable menstrual blood loss 1
• The patient may have already received oral iron supplementation or dietary modifications that corrected the deficiency 1
• TSAT and ferritin levels must be current to avoid unnecessary IV iron administration and potential iron overload 1
• Insurance payers typically require laboratory confirmation within 3-6 months of treatment 1

Appropriate Diagnostic Workup Required

Before authorizing Feraheme, obtain current (within 30-90 days) laboratory studies including:

• Complete blood count with hemoglobin level 1
• Serum ferritin 1
• Transferrin saturation (TSAT) 1
• Comprehensive metabolic panel to assess renal function 2

The patient must demonstrate current IDA with TSAT <20% and/or ferritin <30 ng/mL to meet medical necessity criteria 1.

Feraheme Dosing and Administration (If Criteria Met)

If updated labs confirm persistent IDA with documented oral iron failure, Feraheme administration is appropriate:

• FDA-approved dosing: 510 mg IV followed by second 510 mg dose 3-7 days later 2
• Alternative evidence-based approach: Single 1020 mg dose over 15-30 minutes has demonstrated equivalent safety and efficacy 1, 3, 4
• No test dose required for ferumoxytol, unlike iron dextran 1
• Infusion should start slowly with observation for several minutes before completing administration over 15-30 minutes 1

Documentation of Oral Iron Failure

The clinical information notes "attempt with oral iron/unsuccessful," which satisfies the requirement for oral iron failure 1. However, this must be clearly documented with:

• Specific oral iron formulation tried and duration of therapy 1
• Reason for failure (intolerance, inadequate response, contraindication) 1
• Gastrointestinal side effects if intolerance was the issue 5

Age-Appropriate Considerations

For a 24-year-old female, additional evaluation should address:

• Menstrual history and heavy uterine bleeding as potential ongoing iron loss 5
• Dietary iron intake assessment 1
• Gastrointestinal causes of blood loss or malabsorption (celiac disease, inflammatory bowel disease, H. pylori) 1
• Consideration of hematology referral if anemia persists despite iron repletion 1

Safety Monitoring

If treatment proceeds after updated labs confirm IDA:

• Monitor vital signs during infusion and for 30 minutes post-infusion 1
• Notify radiology if MRI planned within 8 weeks of ferumoxytol administration due to interference with imaging 1
• Reassess hemoglobin, ferritin, and TSAT at 4-8 weeks post-treatment 2, 3
• Expected hemoglobin increase of 1-2.6 g/dL by 4-8 weeks 3, 6

Common Pitfalls to Avoid

Do not authorize IV iron based on outdated laboratory values, as this exposes the patient to unnecessary treatment risks and healthcare costs 1. Iron overload can occur with inappropriate IV iron administration, particularly with TSAT >50% or ferritin >800 ng/mL 1.

Do not proceed without documented oral iron trial failure, as oral iron remains first-line therapy for uncomplicated IDA in patients without malabsorption or severe anemia 1.

Authorization Decision

DENY the current request pending updated laboratory studies. Once current labs (within 30-90 days) confirm persistent IDA with TSAT <20% and/or ferritin <30 ng/mL, and documented oral iron failure is verified, resubmit for approval of Feraheme 510 mg IV x 2 doses 1.