By Counterforce Health Team in Enhertu (fam-trastuzumab deruxtecan-nxki) —

How to Get Enhertu (fam-trastuzumab deruxtecan-nxki) Covered by Humana in Michigan: Prior Authorization Guide and Appeals Process

Answer Box: Getting Enhertu Covered by Humana in Michigan

Enhertu (fam-trastuzumab deruxtecan-nxki) requires prior authorization from Humana Medicare Advantage plans due to its high cost (~$2,440 per 100mg vial) and specialized oncology use. To get coverage in Michigan:

  1. Submit prior authorization via Humana's provider portal with HER2 testing results and treatment history
  2. If denied, file internal appeal within timeframes on denial notice (typically 60 days)
  3. Request Michigan external review through DIFS within 127 days if internal appeal fails

First step today: Have your oncologist check Enhertu's status in Humana's prior authorization search tool and gather HER2 biomarker results before submitting.

Table of Contents

  1. Why Michigan State Rules Matter
  2. Humana Prior Authorization Requirements
  3. Step Therapy Protections in Michigan
  4. Appeals Process: Internal to External Review
  5. Common Denial Reasons & How to Fix Them
  6. Practical Scripts and Templates
  7. When to Contact Michigan DIFS
  8. Costs and Patient Assistance
  9. FAQ

Why Michigan State Rules Matter

Michigan's Patient's Right to Independent Review Act gives you powerful appeal rights that work alongside Humana's policies. Unlike some states, Michigan provides 127 days to file an external review—longer than the federal 120-day standard—and offers expedited reviews within 72 hours for urgent cases.

For Humana Medicare Advantage members, this matters because:

  • Dual protection: Both Medicare appeal rights and Michigan state protections apply
  • Extended deadlines: Michigan's 127-day external review window provides extra time
  • Independent medical review: Michigan assigns cases to Independent Review Organizations (IROs) with oncology expertise
Note: Self-funded employer plans (ERISA) may have different rules, but most individual and small group Humana plans in Michigan follow state regulations.

Humana Prior Authorization Requirements

Enhertu requires prior authorization under Humana's oncology therapy services category. Based on Humana's prior authorization requirements, here's what you need:

Coverage Requirements Table

Requirement What It Means Documentation Needed Source
HER2 status Positive or low expression confirmed Pathology report with IHC/FISH results FDA label
Line of therapy Prior treatment attempts documented Treatment history, progression notes Humana medical policy
Diagnosis codes Cancer type with appropriate ICD-10 C50.x (breast), C16.x (gastric), C78.x (lung) CMS guidelines
Prescriber specialty Oncologist or hematologist-oncologist Provider credentials verification Standard requirement
Site of care Infusion center or hospital outpatient J9358 administration plan Medicare Part B coverage

Submission Process

Submit via these methods:

  • Recommended: Availity portal for electronic submission (Humana targets 95% decisions within 1 business day by 2026)
  • Alternative: CoverMyMeds for pharmacy prior authorization
  • Phone: Call Humana provider services for urgent cases

Step Therapy Protections in Michigan

Michigan allows step therapy exceptions when preferred treatments have failed or are inappropriate. For HER2-targeted therapies like Enhertu, common exceptions include:

Medical Exception Criteria

  • Prior failure: Inadequate response to preferred HER2 agents (trastuzumab, pertuzumab)
  • Contraindications: Heart conditions preventing cardiotoxic agents
  • Intolerance: Documented adverse reactions to first-line options
  • Continuation: Already stable on Enhertu from another plan

Documentation required: Prescriber attestation with specific clinical details about why alternatives won't work.

Tip: Include ejection fraction results if cardiac contraindications apply, or progression imaging if prior treatments failed.

Appeals Process: Internal to External Review

Step-by-Step Appeals Timeline

1. Internal Appeal (Required First Step)

  • Deadline: 60 days from denial notice
  • Timeline: Humana responds within 30 days (pre-service) or 60 days (post-service)
  • Submit via: Member portal, phone (800-457-4708), or mail

2. External Review Through Michigan DIFS

  • Deadline: 127 days from final internal denial
  • Timeline: 60 days maximum (often faster)
  • Submit via: Online form or paper application
  • Cost: Free

3. Expedited External Review (Urgent Cases)

  • Timeline: 72 hours
  • Requirement: Physician letter stating delay would harm patient
  • Use when: Cancer progression, treatment delays risk complications

Required Documents for External Review

  • Copy of Humana's final denial letter
  • Medical records supporting necessity
  • Physician statement on medical urgency (for expedited)
  • Treatment history and alternatives tried

Common Denial Reasons & How to Fix Them

Denial Reason Fix Strategy Key Documents
Missing HER2 testing Submit pathology report IHC 3+ or FISH positive results
"Not first-line therapy" Document prior treatment failures Progression notes, imaging, toxicity records
Site of care restriction Verify infusion center credentials Provider enrollment, facility certification
Dose exceeds guidelines Cite weight-based dosing rationale Patient weight, BSA calculation, FDA label
"Experimental" designation Reference FDA approvals FDA Orange Book entry

Sample Medical Necessity Language

"Patient has HER2-positive metastatic breast cancer with documented progression on trastuzumab/pertuzumab combination therapy. Enhertu is FDA-approved for this indication and represents the standard of care per NCCN guidelines. Alternative agents are contraindicated due to [specific clinical reason]."

Practical Scripts and Templates

Patient Phone Script for Humana

"Hi, I'm calling about a prior authorization denial for Enhertu, reference number [X]. My oncologist says this is medically necessary because [brief reason]. Can you tell me exactly what documentation is missing and how to submit an appeal?"

Clinician Peer-to-Peer Request

"I'm requesting a peer-to-peer review for [patient name] regarding Enhertu coverage. The patient has HER2-positive [cancer type] with progression on standard therapy. I can provide clinical rationale and answer questions about medical necessity."

When to Contact Michigan DIFS

Contact Michigan DIFS at 877-999-6442 when:

  • Humana's internal appeal process exceeds timelines
  • You need help understanding external review eligibility
  • Humana fails to provide required appeal information
  • You want to file a general insurance complaint

DIFS provides free assistance with forms, deadlines, and process questions. They can also investigate potential violations of Michigan insurance law.

Costs and Patient Assistance

Enhertu costs approximately $2,440 per 100mg vial, with total treatment costs depending on patient weight and dosing schedule.

Financial assistance options:

  • Manufacturer copay card: Daiichi Sankyo patient assistance (verify eligibility restrictions)
  • Foundation grants: Patient Access Network, CancerCare, Leukemia & Lymphoma Society
  • Medicare Extra Help: Low-income subsidy for Part D costs
From our advocates: We've seen patients successfully reduce out-of-pocket costs from thousands to hundreds of dollars by combining manufacturer assistance with foundation grants. Start applications early, as processing can take several weeks.

FAQ

How long does Humana prior authorization take for Enhertu in Michigan? Standard decisions within 72 hours; expedited within 24 hours for urgent cases. Humana is working toward 95% same-day decisions by 2026.

What if Enhertu isn't on Humana's formulary? File a formulary exception request with prescriber documentation that covered alternatives are ineffective or cause adverse effects.

Can I get expedited appeals in Michigan? Yes, both Humana (24-hour expedited PA) and Michigan DIFS (72-hour external review) offer expedited processes with physician support letters.

Does step therapy apply if I was stable on Enhertu with another insurer? Michigan supports continuity of care exceptions. Provide documentation of current treatment and clinical stability.

What happens if Michigan DIFS denies my external review? You can pursue judicial review in Michigan circuit court within 60 days, though this is rare for well-documented oncology cases.

Who can help me navigate this process? Counterforce Health specializes in turning insurance denials into evidence-backed appeals, helping patients and clinicians get prescription drugs approved through targeted documentation and payer-specific workflows.

Navigating insurance coverage for specialized cancer treatments like Enhertu can feel overwhelming, but Michigan's strong consumer protections and Humana's improving prior authorization processes provide multiple pathways to approval. The key is thorough documentation, understanding your appeal rights, and knowing when to escalate to state regulators.

For complex cases requiring expert assistance with appeals and documentation, Counterforce Health helps patients, clinicians, and specialty pharmacies transform insurance denials into successful approvals through evidence-based appeals that align with payer requirements and clinical guidelines.

Sources & Further Reading

Disclaimer: This information is for educational purposes only and does not constitute medical or legal advice. Insurance coverage decisions depend on individual circumstances, plan details, and clinical factors. Always consult with your healthcare provider and insurance plan for specific coverage questions. For assistance with appeals, contact Michigan DIFS at 877-999-6442 or visit michigan.gov/difs.

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