Currentsierra health and lifePolicy 2025D0136A

Kebilidi (eladocagene exuparvovec-tneq) — Coverage Criteria for AADC Deficiency

Defines clinical coverage criteria and authorization limits for Kebilidi gene therapy to treat aromatic L‑amino acid decarboxylase (AADC) deficiency for UnitedHealthcare commercial members; applies to providers seeking benefit authorization and payers determining medical necessity.

Policy Summary

Payersierra health and life

PolicyKebilidi (eladocagene exuparvovec-tneq) — Coverage Criteria for AADC Deficiency

Policy CodePolicy 2025D0136A

Change TypeNo material change

Effective DateAug 1, 2025

Next Review DateN/A

Key ActionObtain prior authorization — limited to one lifetime treatment and authorization duration of no more than 60 days from approval.

SourceLink

POLICY UPDATE CHANGES

No material clinical or coverage changes in this revision.

onetreatment allowed per lifetime

≤60dauthorization duration

13pivotal trial patients

1.8e11total dose (vg)

E70.81ICD-10

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Coverage Criteria for Kebilidi (eladocagene exuparvovec-tneq)

Initial Therapy — Kebilidi

Kebilidi is proven and medically necessary when ALL of the following are met:

Initial Coverage Criteria: Genetically confirmed AADC deficiency due to biallelic mutations in the DDC gene.

One or more typical clinical characteristics of AADC deficiency (e.g., hypotonia, oculogyric crises, dystonia, hypokinesia, autonomic dysfunction, developmental delay).

Decreased AADC enzyme activity in plasma per current laboratory standards.

Skull maturity confirmed by neuroimaging sufficient for stereotactic neurosurgical administration.

Persistent symptoms despite use of standard medical therapy (e.g., dopamine agonists, monoamine oxidase inhibitors, pyridoxine, other forms of vitamin B6).

Patient is unable to ambulate independently.

Anti-AAV2 antibody titer not higher than 1:1200 and not >1 optical density by ELISA.

Prescribed by a neurologist or neurosurgeon.

Patient has not previously received Kebilidi or other gene therapy for AADC deficiency in their lifetime.

Dosing is in accordance with the FDA-approved labeling.

Authorization limited to no more than one treatment per lifetime and for no longer than 60 days from approval.

All listed conditions must be satisfied for coverage.

Coverage for Kebilidi (eladocagene exuparvovec-tneq) is conditional on specific exclusionary findings and eligibility constraints. Patients with an anti-AAV2 antibody titer greater than 1:1200 or an optical density value > 1 by ELISA are excluded from coverage. Prior receipt of Kebilidi or any other gene therapy for AADC deficiency in the patient’s lifetime also precludes coverage. Additionally, coverage requires documentation of genetically confirmed biallelic DDC mutations, decreased plasma AADC enzyme activity, skull maturity for stereotactic neurosurgical administration, persistence of symptoms despite standard medical therapy, inability to ambulate independently, and that the therapy is prescribed by a neurologist or neurosurgeon. Dosing must follow the FDA-approved labeling.

Services that do not meet the stated coverage criteria, or that exceed member-specific benefit plan limits, may be denied. The presence of an applicable billing code in this policy does not guarantee coverage or payment; coverage determinations remain subject to the member’s benefit document and applicable laws or mandates. Where Certificate of Coverage terms or state mandates apply, those provisions supersede the general policy language and should be consulted when adjudicating claims.

Instructions for Use and Reference Codes

Instructions for Use / Reference codesmixed

C9399	Unclassified drugs or biologicals.
J3590	Unclassified biologics.
E70.81	Aromatic L-amino acid decarboxylase (AADC) deficiency

Provider Requirements, Authorization & Documentation

Prior Authorization

Prior Authorization Required

Prior authorization required. Authorization is limited to one lifetime treatment and will be issued for no longer than 60 days from approval.

One lifetime treatment per member
Authorization duration ≤ 60 days from approval
Prior authorization required before treatment

Step Therapy

Requirement to Try Standard Medical Therapy

Patient must have persistent symptoms of AADC deficiency despite use of standard medical therapy. Standard medical therapy includes, but is not limited to, dopamine agonists, monoamine oxidase (MAO) inhibitors, pyridoxine (vitamin B6), and other supportive symptomatic agents. Documentation should show failure of or inadequate response to appropriate trials of these therapies.

Documented trial(s) and inadequate response to first-line agents (e.g., dopamine agonists, MAO-inhibitors, pyridoxine)

Background on AADC Deficiency and Therapy

Aromatic L‑amino acid decarboxylase (AADC) deficiency is a rare autosomal condition caused by biallelic pathogenic variants in the DDC gene that lead to deficient AADC enzyme activity and impaired synthesis of dopamine and serotonin. Clinically, affected patients commonly present with movement disorders (for example, hypotonia, oculogyric crises, dystonia, hypokinesia), autonomic dysfunction, and developmental delay. Kebilidi is a one‑time AAV2‑based intraputaminal gene replacement therapy intended to restore AADC enzyme expression and improve neurotransmitter production; coverage is limited to patients who meet the diagnostic, laboratory, and clinical criteria described above.

Key Definitions and Diagnostic Criteria

Kebilidi (eladocagene exuparvovec-tneq) — one-time gene replacement therapy

ProductKebilidi (eladocagene exuparvovec-tneq)

DescriptionOne-time gene replacement therapy delivering a copy of the DDC gene via recombinant adeno-associated virus serotype 2 (AAV2) to cells within the putamen.

Mechanism of actionAAV2-mediated intraputaminal delivery of DDC leads to expression of AADC enzyme in putamen neurons, restoring conversion of L-DOPA and 5-HTP to dopamine and serotonin.

Dosing frequency/limitOne-time treatment (authorization limited to no more than one lifetime treatment).

Clinical intentRestore AADC enzyme expression and subsequent production of dopamine to treat AADC deficiency-related movement and developmental symptoms.

Documentation Required

Required Clinical Documentation

Submit comprehensive clinical documentation with the prior authorization request to support medical necessity. Required documentation includes genetic confirmation and laboratory, clinical, and provider information as specified below.

Genetic confirmation of AADC deficiency due to biallelic pathogenic variants in the DDC gene
Evidence of decreased AADC enzyme activity in plasma per current laboratory standards
Clinical history documenting typical AADC deficiency features (e.g., hypotonia, oculogyric crises, dystonia, hypokinesia, autonomic dysfunction, developmental delay)
Documentation that the patient has achieved skull maturity as confirmed by neuroimaging for stereotactic neurosurgical administration
Documentation that the patient is unable to ambulate independently
Anti-AAV2 antibody testing showing titer ≤ 1:1200 (or ≤ 1 optical density by ELISA)
Prescribing clinician specialty (neurologist or neurosurgeon) and statement that dosing follows FDA-approved labeling
Documentation that the patient has not previously received Kebilidi or other gene therapy for AADC deficiency (no prior lifetime treatment)