Exon‑skipping and gene therapy drugs for Duchenne muscular dystrophy (Amondys 45, Elevidys, Exondys 51, Vyondys 53, Viltepso)
Customize your policy alerts
Sign up for marylandphysicianscarempc Policy RX.PA.009.MPC alerts
Get alerted when Policy RX.PA.009.MPC changes without checking for updates manually.
Monitor payer policy activity
Prior authorization policy defining coverage criteria, initial and reauthorization requirements, and coding for casimersen, delandistrogene moxeparvovec, eteplirsen, golodirsen, and viltolarsen for treatment of Duchenne muscular dystrophy (DMD). Applies to prescribers and members seeking payer coverage under this Maryland Physicians Care policy.
No material clinical or coverage changes in this revision.
Coverage Criteria for Exon-skipping and Gene Therapy Drugs
inv-01: Initial Therapy
Initial Authorization — Must meet ALL of the following:
Applies to all listed products.
Product-specific requirements
- Amondys 45 (casimersen): Age <= 13 years at therapy initiation; confirmed DMD gene mutation amenable to exon 45 skipping (laboratory documentation required); member will not be receiving concomitant exon-skipping therapies or gene therapies for DMD; provider attests that kidney function will be monitored appropriately.
- Elevidys (delandistrogene moxeparvovec): Age 4 to <12 years at therapy initiation; confirmed DMD gene mutation and MUST NOT have any deletion in exon 8 and/or exon 9 (laboratory documentation required); member must initiate a corticosteroid regimen prior to infusion and continue treatment for a minimum of 60 days after infusion; baseline testing for anti-AAVrh74 total binding antibodies prior to infusion; monitor liver function before infusion and weekly for the first 3 months after infusion; monitor troponin-I before infusion and weekly for the first month after infusion; monitor platelet count before infusion and weekly for the first 2 weeks after infusion; member will not be receiving exon-skipping therapies for DMD concomitantly or following Elevidys treatment; member has not received prior Elevidys treatment.
Elevidys is a one-time, lifetime therapy; reauthorization is not applicable.
- Exondys 51 (eteplirsen): Age >= 7 years; confirmed DMD gene mutation amenable to exon 51 skipping (laboratory documentation required); member will not be receiving concomitant exon-skipping therapies or gene therapies for DMD.
- Vyondys 53 (golodirsen): Age >= 6 years; confirmed DMD gene mutation amenable to exon 53 skipping (laboratory documentation required); provider attests to monitoring renal function at baseline and during the course of treatment; member will not be receiving concomitant exon-skipping therapies or gene therapies for DMD.
- Viltepso (viltolarsen): Age <= 9 years at therapy initiation; confirmed DMD gene mutation amenable to exon 53 skipping (laboratory documentation required); baseline physical function demonstrating either 6-minute walk test (6MWT) >= 300 meters while walking independently OR Brooke Upper Extremity Scale score <= 5 OR forced vital capacity (FVC) >= 50%; member does not have medically intractable congestive heart failure and is not ventilator dependent; member will not be receiving concomitant exon-skipping therapies or gene therapies for DMD.6MWT >= 300 meters OR Brooke <= 5 OR FVC >= 50%
inv-02: Reauthorization
Reauthorization — (Not applicable for Elevidys)
Authorization may be extended for 1 year based on these criteria.
inv-03: Not Covered / Investigational
Any use of Amondys 45, Elevidys, Exondys 51, Vyondys 53, or Viltepso outside their FDA‑approved indications is considered investigational/experimental and therefore not covered.
Use of these products for non–FDA‑approved indications is explicitly not covered and is classified as investigational/experimental under this policy.
Product-specific Initial Therapy Requirements
inv-13: Initial Therapy
Product-specific initial criteria (must meet all all-products criteria plus the product-specific items):
Elevidys is a one-time, lifetime therapy; reauthorization not applicable.
Continuation / Renewal Requirements
inv-14: Continuation Therapy
Continuation/renewal requirements (annual):
Elevidys is a one-time therapy; reauthorization is not applicable for Elevidys.
Provider Obligations, Documentation, and Review
Prior authorization required for all products
Prior authorization is required for all listed products. Initial approvals require that the prescriber specialty, patient sex assigned at birth, DMD diagnosis, ambulatory status with ability to complete a 6-minute walk test, an adequate trial of ≥12 weeks of corticosteroids (or documented intolerance/contraindication), dosing within the manufacturer's FDA labeling, and any applicable product-specific eligibility (age and mutation documentation, monitoring attestations, and other product requirements) are met.
- Prescriber must be a neurologist who specializes in muscular dystrophy.
- Documentation of mutation amenable to the specific exon skipping (or mutation requirements for Elevidys) is required per product.
- Dosing must be within the manufacturer's FDA-approved labeling.
No step therapy between listed drugs; no concomitant exon-skipping or gene therapy
The policy does not impose step therapy between the listed agents; however, it requires that patients not receive concomitant exon-skipping therapies or gene therapies and that an adequate corticosteroid trial (≥12 weeks) be completed prior to initiation of exon-skipping agents unless there is a contraindication or significant toxicity.
- Member must not be receiving concomitant exon-skipping therapies or gene therapies for DMD (applies across products and specifically for Elevidys where post-treatment exon-skipping is prohibited).
- Policy requires an adequate trial of at least 12 weeks of corticosteroids prior to initiation of exon-skipping therapies unless significant side effects/toxicity or contraindication exist.
Provide mutation lab confirmation and required clinical monitoring
Documentation submitted with the request must include laboratory confirmation of the member's DMD gene mutation that is amenable to the specific exon skipping (or the specific mutation absence required for Elevidys), baseline and ongoing clinical assessments (e.g., 6MWT, Brooke scale, FVC), and for renewals chart documentation that the member remains a candidate and has stabilized or improved on therapy; Vyondys 53 renewals must include recent renal function tests (GFR).
- Product-specific lab confirmation of the DMD mutation amenable to the indicated exon skipping is required (Elevidys requires documentation that there is no deletion in exon 8 and/or exon 9).
- Baseline and follow-up assessments such as 6-minute walk test, Brooke Upper Extremity Scale, and FVC must be documented.
- For Vyondys 53 renewals include recent renal function tests; baseline GFR must be > 30 mL/min/m2 and member must not have moderate to severe renal impairment.
Requests not meeting criteria may be referred to Medical Director and denied
If the established authorization criteria are not met, the request will be referred for Medical Director review and may be denied based on that review and the plan's requirements.
- Initial authorization limitations specify up to 6 months (Elevidys is a one-time, lifetime approval) and reauthorization up to 1 year where applicable; failure to meet criteria may trigger Medical Director review.
Billing and HCPCS Codes
Step Therapy and Prior Medication Requirements
| Requirement | Details |
|---|---|
| Corticosteroid trial | |
| Adequate trial of at least 12 weeks of corticosteroids prior to initiation of exon‑skipping therapies unless the member has significant side effects/toxicity or a contraindication to corticosteroids |
Administration and Monitoring Requirements
Infusion administration and required monitoring for Elevidys
Elevidys requires infusion administration with specified pre- and post-infusion monitoring: baseline anti-AAVrh74 antibody testing and monitoring of liver function, troponin‑I, and platelet count per the schedule; infusion administration and these monitoring requirements imply care in an infusion setting.
- Baseline testing for anti-AAVrh74 total binding antibodies prior to infusion.
- Monitor liver function before infusion and weekly for the first 3 months after infusion.
- Monitor troponin‑I before infusion and weekly for the first month after infusion.
- Monitor platelet count before infusion and weekly for the first 2 weeks after infusion.
- Member must initiate and continue a corticosteroid regimen per Elevidys requirements (start prior to infusion and continue ≥60 days after).
Key Definitions
Background and Epidemiology
Duchenne muscular dystrophy (DMD) is a rare, X‑linked, recessive, degenerative neuromuscular disease caused by mutations in the DMD gene that result in defective or absent dystrophin, leading to progressive muscle degeneration, loss of ambulation, and respiratory and cardiac complications. This policy addresses exon‑skipping antisense oligonucleotide therapies and an AAV‑based gene transfer product that are indicated for specific DMD mutation subgroups.
OpenPayer is powered by Trek Health's payer performance platform. Trek continuously ingests, validates, and normalizes Transparency in Coverage data alongside payer policies and other commercial payer data to create a structured payer intelligence foundation. OpenPayer uses this foundation to deliver personalized search results, dynamically generated policy pages, and tailored policy monitoring based on each user's payers, specialties, billing codes, and areas of interest. The same intelligence powers broader payer performance workflows, including reimbursement benchmarking, contract evaluation, payer negotiations, and financial decision-making.