CurrentUnitedHealthcarePolicy 2025D0136A

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

Policy governs medical benefit coverage and authorization criteria for Kebilidi gene therapy to treat aromatic L‑amino acid decarboxylase (AADC) deficiency for UnitedHealthcare commercial lines; applies to providers submitting requests for this therapy.

Policy Summary

PayerUnitedHealthcare

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

Policy CodePolicy 2025D0136A

Change TypeNo material clinical or coverage changes

Effective DateAug 1, 2025

Next Review DateN/A

Key ActionSubmit prior authorization with required documentation including genetically confirmed biallelic DDC mutations, decreased AADC enzyme activity, skull maturity imaging, evidence of prior standard therapies, and confirmation patient has not previously received gene therapy.

SourceLink

POLICY UPDATE CHANGES

No material clinical or coverage changes in this revision.

onetreatment allowed per lifetime

60 daysauthorization window

1.8e11 vgpivotal study dose

13trial subjects

E70.81ICD-10 code

Coverage Criteria for Kebilidi (eladocagene exuparvovec-tneq)

Proven / Medically Necessary criteria for Kebilidi

Covered when ALL of the following are met:

Genetic diagnosis: Genetically confirmed AADC deficiency due to biallelic mutations in the dopa decarboxylase (DDC) gene

Submit medical records documenting genetic confirmation.

Clinical features: Patient has one or more typical clinical characteristics associated with AADC deficiency (e.g., hypotonia, oculogyric crises, dystonia, hypokinesia, autonomic dysfunction, developmental delay)

Document clinical signs in medical record.

Enzyme activity: Decreased AADC enzyme activity in plasma per current laboratory standards

Provide laboratory results demonstrating decreased AADC activity.

Policy Summary

PayerUnitedHealthcare

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

Policy CodePolicy 2025D0136A

Change TypeNo material clinical or coverage changes

Effective DateAug 1, 2025

Next Review DateN/A

SourceLink

On This Page

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Skull maturity: Patient has achieved skull maturity as confirmed by neuroimaging necessary for stereotactic neurosurgical administration of Kebilidi

Include neuroimaging report confirming skull maturity for intraputaminal delivery.

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

Document prior and failed/insufficient response to standard therapies.

Mobility: Patient is unable to ambulate independently

Document functional mobility status.

Anti-AAV2 antibody titer is not higher than 1:1200 or > 1 optical density value by ELISA<= 1:1200 or <= 1 OD by ELISA

Provide antibody titer/ELISA results; titers above this threshold exclude coverage.

Prescriber: Prescribed by a neurologist or neurosurgeon

Include prescriber specialty in request.

No prior gene therapy: Patient has not previously received treatment with Kebilidi or other gene therapy for the treatment of AADC deficiency in their lifetime

Authorization limited to one lifetime treatment; verify prior therapy history.

Dosing is in accordance with the United States Food and Drug Administration approved labeling

Treatment must follow FDA-approved dosing regimen.

Authorization window: Authorization will be issued for no more than one treatment per lifetime and for no longer than 60 days from approval<= 60 days

Authorization is limited to a single lifetime treatment and a 60-day window from approval for delivery.

Patients with an anti‑adeno‑associated virus, serotype 2 (anti‑AAV2) antibody titer higher than 1:1200 or greater than 1 optical density (OD) by enzyme‑linked immunosorbent assay (ELISA) are excluded from coverage for Kebilidi.

Repeat treatments or any treatment beyond a single lifetime administration are not authorized. Authorization will be issued for no more than one treatment per lifetime and, when approved, coverage is limited to the approved treatment period.

Applicable Codes and Coding-Related Criteria

Applicable Codes (reference)mixed

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

Anti-AAV2 antibody titer — required threshold

Required thresholdAnti-AAV2 antibody titer must not be higher than 1:1200 or greater than 1 optical density (OD) by ELISA.

Consequence of exceeding thresholdPatients with anti-AAV2 antibody titer higher than 1:1200 or >1 OD by ELISA are excluded from coverage.

Assay specifiedThreshold referenced to enzyme-linked immunosorbent assay (ELISA) optical density value (>1 OD).

Prior Authorization, Documentation, and Provider Responsibilities

Prior Authorization

Prior Authorization Required

Prior authorization is required before administration of Kebilidi (eladocagene exuparvovec‑tneq). Authorization will be issued for no more than one lifetime treatment and for a duration not to exceed 60 days from approval. Dosing must follow the FDA‑approved labeling. Submit prior authorization requests to UnitedHealthcare per standard plan procedures.

One lifetime treatment limit
Authorization duration: up to 60 days from approval
Dosing per FDA‑approved labeling
Submit PA to UnitedHealthcare prior to service

Documentation Required

Required Documentation

Prior authorization requests must include complete documentation demonstrating that the patient meets all coverage criteria. Missing or incomplete documentation is a basis for denial. Examples of required documentation include genetic testing results, laboratory enzyme activity, neuroimaging confirming skull maturity for stereotactic administration, clinical characterization of symptoms, prior medication trials, and documentation that the patient has not previously received Kebilidi or any other gene therapy for AADC deficiency.

Genetically confirmed AADC deficiency due to biallelic DDC mutations
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)
Neuroimaging confirming skull maturity required for stereotactic neurosurgical administration
Documentation of prior therapies and persistent symptoms despite standard medical therapy (e.g., dopamine agonists, MAO inhibitors, pyridoxine/vitamin B6)
Statement that the patient has not previously received Kebilidi or other gene therapy for AADC deficiency
Anti‑AAV2 antibody titer results demonstrating titer ≤ 1:1200 and OD ≤ 1 by ELISA
Prescription by a neurologist or neurosurgeon

Denial Risk

Triggers for Denial

Denial may be issued when required documentation is missing, incomplete, or when exclusionary clinical or laboratory findings are present. Common triggers for denial include lack of genetic confirmation, absent or non‑confirmatory AADC enzyme activity testing, anti‑AAV2 antibody titer above allowable threshold, prior receipt of gene therapy for AADC deficiency, lack of documentation of prior adequate medical therapy trials, or neuroimaging that does not confirm skull maturity for safe stereotactic delivery.

No genetic confirmation of biallelic DDC mutations
No demonstrated decrease in AADC enzyme activity
Anti‑AAV2 antibody titer > 1:1200 or OD value > 1 by ELISA
Prior treatment with Kebilidi or other gene therapy for AADC deficiency
No documentation of persistent symptoms despite standard therapy
Neuroimaging does not confirm skull maturity for stereotactic administration

Step Therapy

Requirement for Prior Medical Therapy

Therapy is indicated only for patients with persistent symptoms of AADC deficiency despite adequate trials of standard medical therapy. Documentation must show that symptoms (for example hypotonia, oculogyric crises, dystonia, hypokinesia, autonomic dysfunction, developmental delay) have continued despite use of first‑line agents such as selective dopamine agonists, monoamine oxidase inhibitors, and pyridoxine (vitamin B6), and any additional symptomatic agents as clinically appropriate.

Document trials of first‑line therapies: dopamine agonists, MAO inhibitors, pyridoxine
Document additional symptomatic treatments as applicable (anticholinergics, melatonin, benzodiazepines, alpha‑adrenoreceptor blockers)
Document persistent symptoms despite stepwise medication management

Definitions and Key Terms

AADC deficiency — definition, genetic cause, enzyme impact

DefinitionAromatic L-amino acid decarboxylase (AADC) deficiency is a rare genetic neurological disorder caused by biallelic pathogenic variants in the dopa decarboxylase (DDC) gene.

Genetic causeBiallelic mutations/pathogenic variants in the DDC gene (dopa decarboxylase).

Enzyme impactResults in deficient AADC enzyme activity leading to inability to synthesize dopamine and serotonin from L-DOPA and 5‑HTP.

Skull maturity — neuroimaging confirmation requirement for stereotactic administration

RequirementNeuroimaging confirmation that the patient has achieved skull maturity sufficient for stereotactic neurosurgical administration of intraputaminal gene therapy.

PurposeEnsures safe stereotactic placement of Kebilidi into the putamen per procedural requirements.

DocumentationSubmit neuroimaging demonstrating skull maturity as part of required medical records for authorization.

Background

Aromatic L‑amino acid decarboxylase (AADC) deficiency is a rare autosomal genetic disorder caused by biallelic pathogenic variants in the dopa decarboxylase (DDC) gene that result in deficient AADC enzyme activity and impaired synthesis of dopamine and serotonin. Clinically, patients present with movement and developmental manifestations such as hypotonia, oculogyric crises, dystonia, hypokinesia, autonomic dysfunction, and developmental delay.

Kebilidi (eladocagene exuparvovec‑tneq) is an AAV2‑based gene replacement therapy delivered to the putamen via stereotactic neurosurgical administration with the goal of restoring AADC enzyme expression and dopamine production. Use is limited to patients with genetically confirmed biallelic DDC mutations, decreased AADC enzyme activity, neuroimaging confirmation of skull maturity for intraputaminal delivery, and who remain symptomatic despite standard medical therapies.