Pegzilarginase-nbln (Loargys) (CPB 1101, reviewed 26-2026-06)

IMMEDIATELY: 1) Billing team must create precertification workflow in billing system requiring prior auth authorization call to (866) 752-7021 or fax to (888) 267-3277 BEFORE any Loargys claims are submitted for Aetna commercial plans. 2) Front desk and authorization staff: Flag all Loargys prescription requests and route to specialty pharmacy precertification team—do not allow claims processing without documented precertification. 3) Providers prescribing Loargys must be board-certified or consulting with physicians specializing in enzyme/metabolic disorders; verify credentials before authorization. 4) Billing system: Configure to REJECT any Loargys claims for patients outside age range 2-31 years or lacking documented baseline plasma arginine level ≥250 micromol/L prior to treatment initiation. 5) Create encounter form checklist requiring: confirmed ARG1-D diagnosis (pathogenic variant OR arginase enzyme assay <1% normal), documented dietary protein restriction plan, exclusion of active infections/HIV/hepatitis/hypersensitivity to polyethylene glycol, and NO prior liver or hematopoietic transplant. 6) Configure billing software to cap approved doses at 0.2 mg/kg once weekly and flag any reauthorization claims for members without pre-dose plasma arginine levels between 50-150 micromol/L. Failure to obtain precertification will result in automatic claim denials from Aetna.