CurrentColorado Rocky Mountain Health PlansPolicy 2025D0136A

Kebilidi™ (Eladocagene Exuparvovec-Tneq) – Commercial Medical Benefit Drug Policy

Defines medical benefit drug coverage criteria, applicable billing codes, clinical background, and policy history for Kebilidi (eladocagene exuparvovec-tneq) as a one-time gene therapy for aromatic L-amino acid decarboxylase (AADC) deficiency under UnitedHealthcare commercial/community plan policy.

Policy Summary

PayerColorado Rocky Mountain Health Plans

PolicyKebilidi™ (Eladocagene Exuparvovec-Tneq) – Commercial Medical Benefit Drug Policy

Policy CodePolicy 2025D0136A

Change TypeNew policy; minor formatting revision

Effective DateAug 1, 2025

Next Review Date

Key ActionObtain prior authorization; authorization will be issued for no more than one lifetime treatment and for no longer than 60 days from approval.

SourceLink

POLICY UPDATE CHANGES

New Medical Benefit Drug Policy

Corrected formatting error in References section

1Lifetime treatments allowed

60 daysAuthorization duration limit

1:1200Anti-AAV2 antibody titer threshold

N=13Pivotal trial treated patients

67%

Coverage Summary & Criteria

Kebilidi (eladocagene exuparvovec-tneq) is covered with criteria as a medical benefit drug for the treatment of aromatic L-amino acid decarboxylase (AADC) deficiency when all policy criteria are met. This policy defines the medical benefit drug coverage criteria, applicable billing codes, clinical background, and policy history for one-time administration of Kebilidi for AADC deficiency.

Medically Necessary / Coverage Criteria

Kebilidi is proven and medically necessary for the treatment of AADC deficiency in patients who meet ALL of the following criteria:

Diagnostic confirmation: Submission of medical records documenting genetically confirmed AADC deficiency due to biallelic mutations in the dopa decarboxylase (DDC) gene
Clinical features: Medical records document the patient has one or more typical clinical characteristics associated with AADC deficiency (e.g., hypotonia, oculogyric crises, dystonia, hypokinesia, autonomic dysfunction, developmental delay)
Biochemical confirmation: Decreased AADC enzyme activity in plasma per current laboratory standards
Anatomic suitability: Patient has achieved skull maturity, as confirmed by neuroimaging, necessary for stereotactic neurosurgical administration of Kebilidi
Prior therapy failure: Patient has persistent symptoms of AADC deficiency despite use of standard medical therapy (e.g., dopamine agonists, monoamine oxidase inhibitors, pyridoxine, other forms of vitamin B6)
Functional status: Patient is unable to ambulate independently
Anti-AAV2 antibody titer: Patient does not have an anti-AAV2 antibody titer higher than 1:1200 or greater than 1 optical density value by ELISAanti-AAV2 antibody titer <= 1:1200 AND optical density <= 1 by ELISA
Prescriber: Prescribed by a neurologist or neurosurgeon
Prior gene therapy: Patient has not previously received treatment with Kebilidi or other gene therapy for the treatment of AADC deficiency in their lifetime
Single lifetime treatment
Dosing is in accordance with the U.S. Food and Drug Administration approved labeling
Authorization duration: Authorization will be issued for no more than one treatment per lifetime and for no longer than 60 days from approval
Authorization duration limit = 60 days from approval

Key thresholds and quick facts

Lifetime treatments allowed1

Authorization duration limit60 days

Anti-AAV2 antibody titer threshold<= 1:1200 (or optical density <= 1 by ELISA)

Prior Authorization, Documentation & Billing Requirements

Prior Authorization

Authorization required and limited

Obtain prior authorization before treatment. Authorization is limited to a single lifetime treatment and will be issued for no longer than 60 days from approval.

Documentation Required

Medical record submission requirements

Submit medical records documenting genetically confirmed biallelic DDC mutations, one or more typical clinical characteristics of AADC deficiency, decreased AADC enzyme activity in plasma per current laboratory standards, confirmation of skull maturity by neuroimaging, documentation of prior use of standard medical therapies, results of anti-AAV2 antibody testing, and documentation that the patient has not received prior gene therapy.

Applicable Codes

Unclassified drug/biologic procedure codes (reference only)HCPCS|Diagnosis

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

Pivotal Study & Outcomes

Phase 2, n=13Pivotal study design

Increase in CSF HVA at Week 8Primary endpoint result

67% new gross motor milestone at Week 48Clinical milestone (treated)

The pivotal evidence comes from a Phase 2, open-label, single-arm study (NCT04903288) with 13 treated patients and a primary assessment at 48 weeks. The primary endpoint showed an increase in CSF homovanillic acid (HVA) by Week 8 in all treated patients, and at Week 48, 8 of 12 (67%) evaluable patients achieved a new gross motor milestone.

Clinical Background & Definitions

Kebilidi (eladocagene exuparvovec-tneq) is a one-time AAV2 vector–based gene replacement therapy that delivers a functional copy of the DDC gene to cells within the putamen to restore AADC enzyme expression and subsequent dopamine production.

AADC deficiency is a rare autosomal recessive neurologic disorder caused by biallelic pathogenic variants in the DDC gene, resulting in impaired synthesis of dopamine and serotonin. Clinically, patients typically present with severe motor and developmental manifestations including hypotonia, oculogyric crises, dystonia, hypokinesia, autonomic dysfunction, behavioral problems, and developmental delay.

Term	Definition
AADC deficiency
Aromatic L-amino acid decarboxylase deficiency due to biallelic pathogenic variants in the DDC gene causing impaired synthesis of dopamine and serotonin.
anti-AAV2 antibody titer
Serologic measure of antibodies against adeno-associated virus serotype 2; threshold for eligibility is <=1:1200 or optical density <=1 by ELISA.

Policy Revision Timeline

2025-08-01added

Policy created as of 08/01/2025

2025-09-01revisedLatest

09/01/2025 administrative formatting correction