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

Myths vs. Facts: Getting Enhertu (fam-trastuzumab deruxtecan-nxki) Covered by Cigna in Michigan - Appeals Guide 2025

Quick Answer: Getting Enhertu covered by Cigna in Michigan requires prior authorization with HER2 biomarker documentation and proof of prior therapy failure. If denied, you have 180 days for internal appeals and 127 days for Michigan DIFS external review. Start by gathering your HER2 pathology report and treatment history today. Submit appeals through Cigna's member portal.

Table of Contents

Why Myths About Enhertu Coverage Persist

Enhertu (fam-trastuzumab deruxtecan-nxki) coverage myths spread because this HER2-targeted therapy is relatively new, expensive (~$2,440 per 100mg vial), and has complex approval criteria that vary by cancer type. Patients often receive conflicting information from different sources, leading to confusion about what's actually required for Cigna approval in Michigan.

The reality is that Enhertu coverage follows predictable patterns, but misinformation can cost you valuable time when every treatment day matters.

Common Myths vs. Facts

Myth 1: "If my oncologist prescribes Enhertu, Cigna has to cover it"

Fact: Cigna requires prior authorization for Enhertu regardless of your doctor's prescription. Your oncologist must submit detailed documentation including HER2 biomarker testing results and proof of prior therapy failure or intolerance. Cigna's oncology coverage policy clearly outlines these requirements.

Myth 2: "HER2-low breast cancer means automatic denial"

Fact: Cigna covers Enhertu for HER2-low breast cancer when properly documented. You need pathology reports showing IHC 1+ or IHC 2+/ISH-negative results from a CLIA-certified lab, plus evidence of prior chemotherapy failure. The key is complete HER2 testing documentation following ASCO/CAP guidelines.

Myth 3: "Step therapy always requires trying cheaper drugs first"

Fact: You can get step therapy overrides if previous treatments failed, caused intolerable side effects, or are contraindicated. Cigna must decide within 72 hours for standard requests and 24 hours for urgent cases when your physician provides supporting documentation.

Myth 4: "Appeals take months and rarely succeed"

Fact: Michigan's external review process through DIFS decides cases within 60 days (72 hours if expedited), and oncology drug appeals have meaningful success rates when properly documented. You have 127 days to file external review after Cigna's final internal denial.

Myth 5: "Enhertu must be given in a hospital"

Fact: Cigna typically requires non-hospital infusion centers unless you meet specific medical exceptions (under age 12, medically unstable, severe prior reactions, or geographic barriers). Site-of-care policies aim to reduce costs while maintaining safety.

Myth 6: "Medicare and commercial Cigna plans have the same rules"

Fact: Requirements differ between plan types. Medicare Advantage plans follow CMS guidelines with specific formulary tiers, while commercial plans may have different prior authorization criteria and appeal timelines. Always verify your specific plan's requirements.

Myth 7: "If it's FDA-approved, insurance must cover it"

Fact: FDA approval doesn't guarantee coverage. Cigna evaluates medical necessity, formulary status, and cost-effectiveness. Even FDA-approved drugs can be denied for "not medically necessary" or formulary exclusion reasons.

Myth 8: "Patient assistance programs replace insurance coverage"

Fact: Manufacturer copay cards and patient assistance programs supplement insurance coverage but don't replace it. You still need prior authorization approval. These programs help with out-of-pocket costs once coverage is established.

What Actually Influences Approval

Documentation Requirements

  • HER2 biomarker testing: Complete pathology report with IHC scores, ISH results (if performed), and CLIA certification
  • Treatment history: Detailed records of prior therapies, dates, outcomes, and reasons for discontinuation
  • Diagnosis codes: Accurate ICD-10 codes matching your cancer type and stage
  • Clinical justification: Letter from your oncologist explaining medical necessity

Coverage Criteria by Cancer Type

HER2-positive breast cancer: Prior trastuzumab/pertuzumab or T-DM1 failure HER2-low breast cancer: Prior chemotherapy in metastatic setting HER2-mutant NSCLC: Prior platinum-based chemotherapy HER2-positive gastric cancer: Prior HER2-targeted therapy

Site of Care Factors

Cigna evaluates whether hospital-based infusion is medically necessary based on:

  • Patient age and stability
  • Comorbidities requiring hospital-level monitoring
  • History of severe infusion reactions
  • Geographic access to outpatient facilities

Avoid These Critical Mistakes

1. Incomplete HER2 Testing Documentation

Missing IHC scores, ISH results, or using non-CLIA certified labs leads to automatic denials. Ensure your pathology report includes all required elements per ASCO/CAP guidelines.

2. Insufficient Prior Therapy Documentation

Vague statements like "patient failed prior treatment" aren't enough. Include specific drug names, dates, duration, and detailed reasons for discontinuation (progression, toxicity, intolerance).

3. Wrong Site of Care Requests

Requesting hospital-based infusion without medical justification triggers denials. Document specific medical reasons if hospital administration is necessary.

4. Missing Appeal Deadlines

Michigan gives you 127 days for external review, but internal appeals have shorter windows. Track all deadlines carefully and file promptly.

5. Inadequate Medical Necessity Letters

Generic letters lacking specific clinical details, guideline citations, and treatment rationale are easily denied. Include peer-reviewed evidence supporting Enhertu use for your specific situation.

Your 3-Step Action Plan

Step 1: Gather Required Documentation (Today)

  • Request complete HER2 pathology report from your lab
  • Collect all prior treatment records with dates and outcomes
  • Obtain current imaging and lab results
  • Verify your Cigna plan's specific formulary status for Enhertu

Step 2: Work with Your Oncologist (This Week)

  • Schedule appointment to discuss prior authorization strategy
  • Request detailed medical necessity letter citing relevant guidelines
  • Confirm site of care preferences and medical justification
  • Submit prior authorization through Cigna provider portal

Step 3: Prepare for Potential Appeals (Within 30 Days)

  • Set up tracking system for all correspondence and deadlines
  • Identify supporting literature and clinical evidence
  • Research Michigan DIFS external review process
  • Consider contacting Counterforce Health for specialized appeals assistance
From our advocates: We've seen cases where patients received denials for "insufficient documentation" when their HER2 testing was complete but reported in non-standard format. Always request your pathology report be formatted according to current ASCO/CAP guidelines before submission. This simple step has helped overturn numerous initial denials.

Michigan-Specific Appeals Process

Internal Appeals with Cigna

  • First level: 180 days from denial to file
  • Timeline: 30 days for standard, 72 hours for urgent
  • Requirements: Written request with supporting documentation

External Review through Michigan DIFS

  • Deadline: 127 days after final internal denial
  • Timeline: 60 days for standard, 72 hours for expedited
  • Process: Submit form online or mail to DIFS
  • Cost: Free for consumers
  • Decision: Binding on Cigna

Expedited Appeals

Available when delay could seriously jeopardize health. Requires physician documentation of urgency and potential harm from treatment delay.

Michigan DIFS Consumer Hotline: 877-999-6442 (Monday-Friday, 8 AM-5 PM)

FAQ

Q: How long does Cigna prior authorization take for Enhertu in Michigan? A: Standard requests: up to 15 business days. Urgent requests: 72 hours with physician documentation of urgency.

Q: What if Enhertu isn't on my Cigna formulary? A: Request a formulary exception with clinical justification. Cigna has 72 hours to decide on standard requests.

Q: Can I get expedited external review in Michigan? A: Yes, if your physician documents that delay would seriously jeopardize your health. DIFS decides expedited cases within 72 hours.

Q: Does step therapy apply if I received treatment outside Michigan? A: Yes, prior treatments from any state count toward step therapy requirements if properly documented.

Q: What counts as medical necessity for Enhertu? A: HER2-positive or HER2-low tumor status, appropriate line of therapy, prior treatment failure/intolerance, and absence of contraindications per FDA labeling.

Q: How much does Enhertu cost without insurance? A: Approximately $2,440 per 100mg vial, with total monthly costs varying by weight-based dosing. Patient assistance programs may help eligible patients.

Coverage at a Glance

Requirement What It Means Where to Find It Source
Prior Authorization Required for all Enhertu prescriptions Cigna provider portal Cigna PA Policy
HER2 Testing Complete pathology with IHC/ISH results CLIA-certified lab report ASCO/CAP Guidelines
Step Therapy Prior HER2-targeted or chemotherapy Treatment records and notes Plan-specific policy
Site of Care Non-hospital preferred Medical justification letter Site of Care Policy
Appeals Deadline 127 days for external review Denial letter date Michigan DIFS

Counterforce Health specializes in turning insurance denials into successful appeals by analyzing denial letters, plan policies, and clinical notes to create targeted, evidence-backed rebuttals. Our platform identifies the specific denial basis and drafts point-by-point responses aligned to each payer's own rules, helping patients, clinicians, and specialty pharmacies get prescription drugs approved more efficiently.

Resources

Official Sources

Patient Support

Professional Guidelines

Disclaimer: This information is for educational purposes only and does not constitute medical or legal advice. Insurance coverage decisions depend on individual circumstances, specific plan terms, and current policies. Always consult with your healthcare provider and insurance company for personalized guidance. For questions about Michigan insurance regulations, contact the Michigan Department of Insurance and Financial Services at 877-999-6442.

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