By Counterforce Health Team in Amondys 45 (casimersen) —

How to Get Amondys 45 (Casimersen) Covered by Blue Cross Blue Shield Michigan: Complete Prior Authorization & Appeals Guide

Answer Box: Getting Amondys 45 Covered in Michigan

Blue Cross Blue Shield of Michigan (BCBSM) currently considers Amondys 45 (casimersen) investigational/experimental, requiring prior authorization that's typically denied. However, Michigan patients have strong appeal rights through DIFS external review.

Fastest path to approval:

  1. Submit prior authorization with genetic testing confirming exon 45-skippable DMD mutation
  2. If denied (likely), file internal appeal within 180 days
  3. Request DIFS external review within 127 days of final denial

Start today: Contact your neurologist to order genetic testing and gather clinical documentation showing failed corticosteroid therapy.

Table of Contents

Coverage Requirements & Coding Basics

Medical vs. Pharmacy Benefit Pathways

Amondys 45 typically processes under the medical benefit for Blue Cross Blue Shield of Michigan, since it's an IV infusion therapy administered in clinical settings. This affects both coding and prior authorization pathways.

Coverage at a Glance:

Requirement BCBSM Status Documentation Needed Source
Prior Authorization Required Genetic testing, specialist prescription BCBSM PA List
Formulary Status Investigational/Experimental Clinical trial data, medical necessity BCBSM DMD Policy
Step Therapy Not specified Prior corticosteroid use PA Guidelines
Age Limits None listed Age-appropriate dosing Verify with plan
Site of Care Outpatient infusion Infusion center or hospital Medical benefit
Note: BCBSM's 2024 medical policy updates do not include specific coverage criteria for Amondys 45, maintaining its investigational status across all indications.

ICD-10 and Documentation Requirements

Primary Diagnosis Code

ICD-10 Code: G71.01 - Duchenne muscular dystrophy

This is the primary diagnosis code that must appear on all prior authorization requests, claims, and clinical documentation for Amondys 45.

Supporting Documentation Requirements

Essential clinical documentation:

  • Genetic testing results confirming DMD with mutation amenable to exon 45 skipping (approximately 9% of DMD cases)
  • Specialist confirmation from neurologist or DMD specialist
  • Prior therapy history showing corticosteroid use and clinical status
  • Functional assessments (6-minute walk test, North Star Ambulatory Assessment if applicable)

Documentation words that support medical necessity:

  • "Confirmed dystrophin gene mutation amenable to exon 45 skipping"
  • "Failed to maintain functional stability on corticosteroids"
  • "Progressive muscle weakness despite standard care"
  • "Candidate for dystrophin restoration therapy"

Genetic Testing Specifications

The FDA label and payer policies require confirmed mutations amenable to exon 45 skipping, such as:

  • Deletions in exons 44, 46-47, 46-48, 46-49, 46-51, 46-53
  • Testing via MLPA, NGS, or equivalent molecular methods
  • Results must be documented in medical record before therapy initiation

Product Coding: HCPCS, NDC, and Billing Units

Current Billing Information

Important: Specific HCPCS J-codes, NDC numbers, and exact billing units for Amondys 45 are not publicly available in standard payer documents. For accurate billing codes, contact:

  • Sarepta Therapeutics directly for current NDC numbers and dosing calculations
  • SareptAssist (manufacturer support program) for billing guidance
  • Your specialty pharmacy or hospital billing department

Dosing and Units Calculation

Standard dosing: 30 mg/kg weekly via IV infusion Product strength: 100 mg/2 mL vial (verify with current labeling)

Example calculation for billing units:

  • 70 kg patient = 2,100 mg weekly dose
  • Number of vials needed = 21 vials per dose (verify current strength)
  • Units per claim depend on specific HCPCS code structure
Tip: Always verify current NDC numbers and billing units with your specialty pharmacy, as these details change with manufacturing updates.

Clean Prior Authorization Request

BCBSM Submission Process

Submit via: Medication Authorization Request Form Fax: 1-877-325-5979 Timeline: 3-5 business days for standard review

Required Components

1. Patient Information

  • BCBSM member ID and policy details
  • Demographics and contact information
  • ICD-10 code G71.01 with supporting diagnosis

2. Clinical Documentation

  • Genetic test results confirming exon 45-skippable mutation
  • Neurologist or DMD specialist prescription and credentials
  • Prior therapy history (corticosteroids, duration, response)
  • Current functional status and treatment goals

3. Product Details

  • Amondys 45 (casimersen) with exact dosing (30 mg/kg weekly)
  • Administration plan (IV infusion, site of care)
  • Monitoring protocol for safety and efficacy

4. Medical Necessity Justification

  • FDA approval basis (accelerated approval for dystrophin production)
  • Clinical rationale for this specific patient
  • Expected outcomes and monitoring plan
From our advocates: We've seen the strongest approvals include comprehensive genetic testing reports, detailed prior therapy timelines, and clear statements about why standard DMD therapies are insufficient. While outcomes vary, thorough documentation significantly improves approval chances.

Common Denial Reasons & How to Fix Them

Denial Reason How to Overturn Required Documents
"Investigational/experimental" Cite FDA accelerated approval (Feb 2021) FDA approval letter, clinical trial data
"Genetic testing not provided" Submit complete genetic analysis MLPA or NGS results showing exon 45-skippable mutation
"Not prescribed by specialist" Ensure neurologist/DMD specialist signature Provider credentials, specialty board certification
"Insufficient prior therapy" Document corticosteroid history Medication records, response/tolerance documentation
"Lack of monitoring plan" Submit detailed safety protocol Lab monitoring schedule, adverse event tracking plan

Counterforce Health Support

Counterforce Health specializes in turning insurance denials into successful appeals by analyzing payer policies and crafting evidence-based rebuttals. Their platform helps identify specific denial reasons and generates targeted responses aligned with each plan's requirements.

Michigan Appeals Process

Internal Appeal (Required First Step)

Timeline: File within 180 days of initial denial Process: Submit appeal through BCBSM member portal or written request Decision: 30 days for pre-service, 60 days for post-service denials

DIFS External Review

Michigan's Department of Insurance and Financial Services (DIFS) provides independent review under the Patient's Right to Independent Review Act.

Key Timeline: 127 days from final internal denial to file external review

Filing Options:

  1. Online (preferred): DIFS External Review Form
  2. Mail/Fax: FIS 0018 form to DIFS Office of General Counsel, P.O. Box 30220, Lansing, MI 48909-7720

Required Documentation:

  • Final denial letter from BCBSM
  • Complete medical records supporting medical necessity
  • Physician letter confirming treatment urgency (for expedited review)
  • Genetic testing results and specialist recommendations

Review Timelines:

  • Standard: Up to 60 days
  • Expedited: 72 hours (requires physician statement of health jeopardy)

Contact DIFS: 877-999-6442 (8am-5pm ET, Monday-Friday)

Success Factors for Appeals

Strong appeals include:

  • Detailed genetic testing confirming exon 45-skippable mutation
  • Comprehensive prior therapy documentation
  • Specialist letters emphasizing medical necessity
  • FDA approval data and clinical trial results
  • Patient-specific functional decline without treatment

Verification and Pre-Submission Checklist

Cross-Check with BCBSM Resources

Before submitting:

  • Verify current member eligibility and benefits
  • Confirm medical vs. pharmacy benefit pathway
  • Check for any updated coverage policies
  • Review BCBSM provider portal for latest PA requirements

Pre-Submission Audit

Clinical Documentation:

  • ICD-10 code G71.01 correctly documented
  • Genetic testing confirms exon 45-skippable mutation
  • Neurologist/DMD specialist prescription and credentials
  • Prior corticosteroid therapy documented with outcomes

Administrative Requirements:

  • Complete BCBSM authorization form
  • All required signatures and dates
  • Correct member ID and policy information
  • Appropriate site of care specified (outpatient infusion)

Supporting Evidence:

  • FDA approval documentation
  • Clinical trial data if applicable
  • Monitoring and safety protocol
  • Alternative therapy contraindications or failures

Common Pitfalls to Avoid

Documentation errors:

  • Missing genetic testing results
  • Incomplete prior therapy history
  • Non-specialist prescriber
  • Incorrect dosing calculations

Process mistakes:

  • Wrong submission pathway (pharmacy vs. medical benefit)
  • Missing required forms or signatures
  • Insufficient clinical justification
  • Late filing of appeals

FAQ

How long does BCBSM prior authorization take for Amondys 45? Standard review is 3-5 business days. However, given the investigational status, initial denials are common, requiring appeals that extend the timeline significantly.

What if Amondys 45 is non-formulary with BCBSM? It's currently listed as investigational/experimental rather than non-formulary. Submit a formulary exception request with comprehensive medical necessity documentation and be prepared to appeal.

Can I request expedited review for urgent cases? Yes, both BCBSM and Michigan DIFS offer expedited reviews when delays would jeopardize patient health. Requires physician documentation of urgency.

Does step therapy apply if I've tried therapies outside Michigan? Prior therapy from any location counts toward step therapy requirements. Ensure all previous treatments are documented with dates, dosing, and outcomes.

What genetic testing is required for coverage? Testing must confirm DMD with a mutation amenable to exon 45 skipping (about 9% of DMD cases). MLPA or NGS testing showing specific deletions like exons 44, 46-47, 46-48, etc.

How much does Amondys 45 cost without insurance? Guide prices show approximately $1,570.78 for a 2 mL (100 mg) vial, though actual costs vary significantly. Annual treatment costs can exceed $300,000.

What manufacturer support is available? Sarepta Therapeutics offers SareptAssist, which provides coverage navigation, financial assistance, and nursing support. Contact through the Amondys45.com website.

When should I contact Michigan DIFS? File external review within 127 days of BCBSM's final internal denial. Don't wait—this deadline is firm and missing it eliminates your appeal rights.

Sources & Further Reading

For complex cases requiring targeted appeals, Counterforce Health provides specialized support in crafting evidence-based responses to insurance denials.

Disclaimer: This information is for educational purposes only and does not constitute medical or legal advice. Coverage decisions vary by individual circumstances and policy details. Always consult with your healthcare provider and insurance plan for specific guidance. For assistance with insurance appeals in Michigan, contact DIFS at 877-999-6442.

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