Gene Therapy for Aromatic L-amino Acid Decarboxylase Deficiency

This policy covers FDA‑approved gene therapy eladocagene exuparvovec‑tneq (Kebilidi™) administered via bilateral intraputaminal (putamen) infusions in a single stereotactic surgery for patients with genetically or biochemically confirmed aromatic L‑amino acid decarboxylase (AADC) deficiency (e.g., biallelic pathogenic/likely pathogenic DDC variants or combinations of VUS with supportive low plasma AADC activity or CSF/plasma neurotransmitter profiles) who have persistent neurological deficits. Major requirements and limitations include anti‑AAV2 antibody titer <1:1,200, demonstrated skull maturity for stereotactic head‑frame placement, strict adherence to the FDA label dosing/infusion volumes/rate using an FDA‑authorized intraparenchymal cannula, one lifetime administration (re‑treatment investigational), and coverage subject to the member’s benefit plan and applicable state rules.

"Requested therapy proven effective for the relevant diagnosis or procedure according to accepted standards of practice."