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

How to Get Enhertu Covered by Aetna CVS Health in California: Prior Authorization Guide and Appeal Process

Answer Box: Getting Enhertu Covered by Aetna CVS Health in California

Enhertu (fam-trastuzumab deruxtecan-nxki) requires prior authorization from Aetna CVS Health for HER2-positive breast cancer, NSCLC, and gastric cancer. Your fastest path to approval: 1) Gather HER2 test results and prior therapy records, 2) Submit PA request via Availity portal at least 2 weeks before treatment, 3) Include complete clinical documentation per Aetna's Clinical Policy Bulletin 0966. If denied, you have 180 days to appeal and can request California's Independent Medical Review for binding external review.

Table of Contents

  1. Plan Types & Coverage Implications
  2. Formulary Status & Tier Placement
  3. Prior Authorization Requirements
  4. Specialty Pharmacy Requirements
  5. Cost-Share Considerations
  6. Submission Process & Forms
  7. Common Approval Patterns
  8. Appeals Process in California
  9. When to Escalate
  10. FAQ

Plan Types & Coverage Implications

Aetna CVS Health offers multiple plan types in California, each with different coverage rules for specialty medications like Enhertu:

HMO Plans: Require referrals to oncology specialists and typically have stricter utilization management. Your primary care physician must coordinate specialty drug approvals.

PPO Plans: Allow direct access to oncologists but may have higher cost-sharing for out-of-network providers. Prior authorization requirements remain the same regardless of network status.

EPO Plans: Combine aspects of both HMO and PPO plans. No referrals needed, but you must stay in-network for coverage.

Medicare Advantage: Follow Medicare Part B rules for physician-administered drugs like Enhertu, with additional Aetna-specific requirements.

Note: All Aetna CVS Health plans in California require prior authorization for Enhertu regardless of plan type, as listed in their 2025 Precertification List.

Formulary Status & Tier Placement

Enhertu is classified as a specialty medication requiring management through CVS Specialty Pharmacy. While specific tier placement varies by plan, most Aetna formularies place Enhertu in a high-tier specialty category due to its cost and complexity.

Coverage Status: Covered for FDA-approved indications including:

  • HER2-positive breast cancer (metastatic, after prior anti-HER2 therapy)
  • HER2-low and HER2-ultralow breast cancer
  • HER2-mutant non-small cell lung cancer
  • HER2-positive gastric/gastroesophageal junction adenocarcinoma

Alternative Agents: If Enhertu is denied, potential alternatives include:

  • Kadcyla (ado-trastuzumab emtansine)
  • Trastuzumab + pertuzumab combinations
  • Standard chemotherapy regimens per disease type

Prior Authorization Requirements

Aetna requires comprehensive documentation for Enhertu approval based on Clinical Policy Bulletin 0966:

Coverage at a Glance

Requirement What It Means Where to Find It Source
PA Required Must get approval before treatment All Aetna plans Precert List
HER2 Status Documented HER2-positive or HER2-low/ultralow Pathology report Policy 0966
Prior Therapy Evidence of previous treatments Medical records Policy 0966
Disease Status Unresectable/metastatic documented Imaging/staging Policy 0966
ILD Monitoring Plan for lung toxicity screening Treatment protocol FDA Label

Medical Necessity Criteria by Indication

Breast Cancer:

  • HER2-positive unresectable or metastatic disease
  • Prior anti-HER2 therapy in metastatic or adjuvant/neoadjuvant setting
  • For HER2-low: progression on endocrine therapy

NSCLC:

  • Unresectable or metastatic disease with HER2 mutations
  • Prior systemic therapy documented

Gastric Cancer:

  • HER2-positive advanced or metastatic adenocarcinoma
  • Prior trastuzumab-based regimen

Specialty Pharmacy Requirements

Enhertu must be dispensed through CVS Specialty Pharmacy for most Aetna plans. This requirement affects how prescriptions are processed and delivered.

Patient Setup Process:

  1. Enrollment: CVS Specialty will contact patient after PA approval
  2. Coordination: Pharmacy coordinates with infusion center for delivery
  3. Monitoring: Ongoing adherence and safety monitoring included
  4. Billing: Buy-and-bill model using J-code J9358
Tip: Some plans allow alternative specialty pharmacies. Verify with member services at 1-888-632-3862 (Commercial) or 1-800-624-0756 (Medicare).

Cost-Share Considerations

Enhertu costs vary significantly based on your specific plan design. Understanding your benefits helps predict out-of-pocket expenses.

Typical Cost Structure:

  • Medical Benefit: Enhertu is covered under medical benefits (not pharmacy)
  • Deductible: May apply before coinsurance kicks in
  • Coinsurance: Often 10-30% for specialty infused medications
  • Out-of-Pocket Maximum: Annual limit provides cost protection

Cost-Saving Resources:

  • Enhertu Co-pay Program (verify current eligibility)
  • Patient assistance foundations for income-qualified patients
  • Hospital charity care programs

Submission Process & Forms

Step-by-Step: Fastest Path to Approval

  1. Gather Documentation (Patient/Clinic)
    • Insurance card and member ID
    • HER2 testing results (IHC/FISH/NGS)
    • Complete treatment history with dates
    • Current staging and imaging reports
  2. Submit PA Request (Provider)
    • Use Availity Provider Portal or EMR integration
    • Submit at least 2 weeks before planned treatment
    • Include all required clinical documentation
  3. Clinical Review (Aetna)
    • Most decisions within 24 hours for complete submissions
    • Expedited review available for urgent cases (≤72 hours)
  4. Approval Processing (All Parties)
    • CVS Specialty contacts patient for enrollment
    • Coordinate delivery with infusion center
    • Schedule baseline monitoring per ILD protocols

Required Documentation Checklist:

  • Prior authorization form (available via Availity)
  • Pathology report confirming HER2 status
  • Treatment history with response/failure documentation
  • Current staging and performance status
  • ILD monitoring plan
  • Prescriber attestation of medical necessity

Common Approval Patterns

Strong submissions that typically get approved include:

Complete Biomarker Documentation: Clear HER2-positive (3+ by IHC or amplified by FISH) or HER2-low (1-2+ by IHC, non-amplified by FISH) results with laboratory and methodology details.

Prior Therapy Evidence: Detailed records showing progression on or intolerance to standard therapies like trastuzumab-based regimens, with dates and response assessment.

Disease Progression Documentation: Recent imaging demonstrating unresectable or metastatic disease with measurable progression.

Safety Monitoring Plan: Specific protocols for ILD surveillance including baseline chest imaging and symptom monitoring schedule.

Clinician Corner: Medical Necessity Letter

Your medical necessity letter should address these key elements:

Clinical Problem: Patient's specific diagnosis with staging and HER2 status Prior Treatments: Chronological list of therapies with outcomes and reasons for discontinuation
Current Status: Disease progression with supporting imaging/labs Treatment Rationale: Why Enhertu is appropriate based on FDA labeling and guidelines Monitoring Plan: ILD screening protocol and safety assessments Citations: Reference FDA prescribing information and relevant treatment guidelines

Appeals Process in California

If your initial PA request is denied, California offers robust appeal rights with specific timelines:

Internal Appeal (First Level)

  • Deadline: 180 days from denial date
  • Timeline: 72 hours for urgent cases, 30 days for standard
  • Method: Written appeal via Aetna portal or mail per denial letter instructions
  • Documentation: Include all clinical records and medical necessity rationale

Independent Medical Review (External Appeal)

After internal appeal denial, California residents can request binding external review:

  • Regulator: Department of Managed Health Care (DMHC) for HMO/PPO plans
  • Timeline: 45 days for standard, 7 days for expedited cases
  • Process: Independent physician experts review case
  • Contact: DMHC Help Center at 1-888-466-2219
  • Cost: Free to patients
  • Success Rate: High for medically appropriate specialty drug requests

Appeals Playbook

Level Deadline Timeline Where to File Required Forms
Internal 180 days 72h urgent/30d standard Aetna Portal Appeal form per denial letter
External (IMR) After internal denial 45d standard/7d urgent DMHC IMR application

When to Escalate

Contact California regulators if:

  • Aetna doesn't respond within required timelines
  • You need help filing appeals or IMR requests
  • Plan isn't following California insurance laws

DMHC Help Center: 1-888-466-2219 for HMO/PPO plans California Department of Insurance: 1-800-927-4357 for other plan types

FAQ

How long does Aetna CVS Health prior authorization take in California? Most complete submissions are decided within 24 hours. Expedited reviews for urgent cases are completed within 72 hours per Aetna's provider guidelines.

What if Enhertu is non-formulary on my plan? You can request a formulary exception with medical necessity documentation. If denied, California's IMR process provides binding external review for medically appropriate requests.

Can I request an expedited appeal? Yes, if treatment delay would significantly worsen your health condition. Specify urgency in your appeal and provide supporting clinical documentation.

Does step therapy apply if I've tried treatments outside California? Prior therapy from any location counts toward meeting step therapy requirements. Provide complete treatment records with dates and outcomes.

What happens if I can't afford my copay? Explore manufacturer copay assistance, patient foundation grants, and hospital charity care programs. Your treatment team's financial counselor can help identify resources.

How do I prove medical necessity for HER2-low breast cancer? Provide pathology showing HER2 1-2+ by IHC with non-amplified FISH, plus evidence of endocrine therapy progression per FDA labeling.

From Our Advocates: "We've seen many Enhertu denials reversed when patients include comprehensive HER2 testing details and clear documentation of prior therapy failures. The key is submitting complete information upfront rather than piecemeal responses to requests for additional documentation."

Getting specialty cancer medications approved can feel overwhelming, but California's strong consumer protections and Aetna's defined criteria create a clear path forward. Counterforce Health helps patients and clinicians navigate complex prior authorization requirements by analyzing denial letters and crafting targeted, evidence-backed appeals that align with each insurer's specific policies. Their platform identifies the exact denial basis and drafts point-by-point rebuttals using the right clinical evidence and regulatory citations.

When working with your healthcare team, focus on gathering complete documentation upfront and don't hesitate to use California's Independent Medical Review process if needed. The state's high success rate with specialty drug appeals reflects the strength of having independent physician experts evaluate medical necessity.

Sources & Further Reading

Disclaimer: This information is for educational purposes only and does not constitute medical or legal advice. Insurance coverage varies by individual plan. Always verify current policy terms with Aetna CVS Health member services and consult your healthcare team for medical decisions. For personalized assistance with prior authorizations and appeals, consider working with Counterforce Health or other qualified advocacy services.

Powered by Counterforce Health—AI that turns drug denials into evidence-based appeals patients and clinicians can submit today.