CurrentAlliance HealthPolicy Clinical Coverage Policy No:11B-9

Thymus Tissue Implantation (RETHYMIC)

North Carolina Medicaid clinical coverage policy for single-administration allogeneic processed thymus tissue (RETHYMIC) implantation for immune reconstitution in beneficiaries with congenital athymia, describing medical necessity criteria, exclusions, prior approval, billing and reimbursement guidance.

Policy Summary

PayerAlliance Health

PolicyThymus Tissue Implantation (RETHYMIC)

Policy CodePolicy Clinical Coverage Policy No:11B-9

Change TypeNew policyreimbursement amendment

Effective DateJun 1, 2023

Next Review Date

Key ActionObtain prior approval and submit the PA request with supporting records (letter of medical necessity, lab confirmation of congenital athymia, infection control documentation, and HLA matching when applicable) before performing Thymus Tissue Implantation.

SourceLink

POLICY UPDATE CHANGES

Policy created for Thymus Tissue Implantation effective 06/01/2023.

08/15/2023 amended Attachment A Section H to add reimbursement information for inpatient claims.

1Allowed administrations per lifetime

17Maximum beneficiary age for coverage

50 cells/mm3 or 5%Naïve T-cell threshold for diagnosis

Coverage Summary

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This is North Carolina Medicaid Clinical Coverage Policy No:11B-9 for Thymus Tissue Implantation (RETHYMIC). The policy effective date is 06/01/2023 and was last amended/reviewed on 08/15/2023. Coverage stance: covered with criteria for a single administration (once per lifetime) of allogeneic processed thymus tissue for immune reconstitution in beneficiaries with congenital athymia, subject to specified medical necessity and prior approval requirements.

Thresholds and Quick Facts

Allowed administrations per lifetime1

Maximum beneficiary age for coverage17 years

Naïve T-cell threshold for diagnosisfewer than 50 naïve T cells/mm3 (CD45RA+, CD62L+) OR <5% of total T cells naïve phenotype

Age threshold17 years of age and younger

Medical Necessity Criteria

General Medical Necessity Criteria

Medicaid shall cover procedures when medically necessary and the following general criteria are met:

ALL of the following

The procedure, product, or service is individualized, specific, and consistent with symptoms or confirmed diagnosis of the illness or injury under treatment, and not in excess of the beneficiary's needs
The procedure, product, or service can be safely furnished, and no equally effective and more conservative or less costly treatment is available statewide
The procedure, product, or service is furnished in a manner not primarily intended for the convenience of the beneficiary, caretaker, or provider

Specific Criteria Covered for Thymus Tissue Implantation (single administration)

Medicaid shall cover a single administration of allogeneic processed thymus tissue for immune reconstitution in a beneficiary 17 years of age and younger when ALL of the following are met:

ALL of the following

Congenital athymia is confirmed via a circulating T-cell count on flow cytometry demonstrating fewer than 50 naïve T cells/mm3 (CD45RA+, CD62L+) in the peripheral blood or less than 5 percent of total T cells being naïve in phenotypeNaïve T-cell count: <50 cells/mm3 OR <5%
Documentation that infection control measures, consisting of immunoprophylaxis and withholding of immunizations, can reasonably be maintained until the development of thymic function is established
Absence of comorbidities, in the opinion of the treating clinician, that are reasonably likely to result in severe complications, including death from administration of allogeneic processed thymus tissue (examples: pre-existing renal impairment, or cytomegalovirus or Epstein-Barr virus infection)
HLA matching is required, performed and documented in a beneficiary who has received a prior hematopoietic cell transplantation (HCT) or a solid organ transplant

Not Covered / Experimental

Not Covered - General

Medicaid shall not cover when any of the following apply:

ANY of the following

Beneficiary does not meet the eligibility requirements listed in Section 2.0
Beneficiary does not meet the criteria listed in Section 3.0
The procedure, product, or service duplicates another provider's procedure, product, or service
The procedure, product, or service is experimental, investigational, or part of a clinical trial

Not Covered - Specific

Medicaid shall not cover the use of allogeneic processed thymus tissue for the following specific indications:

ANY of the following

Immune reconstitution in a beneficiary with severe combined immunodeficiency (SCID)
Repeat administration in a beneficiary who has previously received allogeneic processed thymus tissue

Provider Actions & Billing Rules

Prior Authorization

Prior approval required

Provider must obtain prior approval before rendering Thymus Tissue Implantation. Use CPT code 60699 in NCTracks when entering the prior approval request.

Enter PA using code 60699
Obtain PA before service

Documentation Required

Submit supporting medical records to Utilization Review Contractor

Submit the prior approval request and all supporting health records to the DHHS Utilization Review Contractor. Required documents include a signed letter of medical necessity, lab results confirming congenital athymia, documentation of infection control measures, and HLA matching documentation when applicable.

Letter of medical necessity signed by attending physician
Lab results confirming congenital athymia (per Subsection 3.2.1)
Documentation of infection control measures (immunoprophylaxis and withholding immunizations)
HLA matching documentation when applicable (prior HCT or solid organ transplant)

Billing Rule

Single administration / Once per lifetime

Thymus Tissue Implantation is authorized as a single administration only (once per lifetime). Repeat or continued administration is not authorized.

One administration per lifetime
Repeat administration is not covered

Billing Rule

Inpatient billing and product reimbursement

Institutional inpatient claims (UB-04/837I) use DRG methodology for the inpatient stay and procedure; include the PA number on the claim. The product RETHYMIC should not be submitted on the inpatient claim — submit via invoice with the required PA number and it will be reimbursed at cost (no markup). Use ICD-10-PCS code XW020D8 for inpatient procedural coding where applicable.

Inpatient claims use DRG methodology; include PA number on claim
RETHYMIC invoiced separately with PA number and reimbursed at cost (not billed on UB-04)
ICD-10-PCS code: XW020D8

Documentation Required

EPSDT considerations for beneficiaries under 21

EPSDT does not eliminate the prior approval requirement for beneficiaries under 21. Providers requesting exceptions under EPSDT must still document medical necessity per EPSDT criteria when requesting exceptions to policy limitations.

EPSDT does not waive the PA requirement
Document how the service meets EPSDT medical necessity when requesting exceptions

Background

RETHYMIC (allogeneic processed thymus tissue) is a regenerative thymus tissue implantation therapy for immune reconstitution in children with congenital athymia, a condition in which a child is born without a thymus and typically experiences severe T-cell lymphopenia and early mortality.

Indication: single administration for immune reconstitution in beneficiaries 17 years of age and younger with confirmed congenital athymia when specific criteria are met (including naïve T-cell thresholds, infection control capability, absence of prohibitive comorbidities, and HLA matching when applicable).

Dosing principles: dosing is patient-customized and determined by the surface area of the RETHYMIC slices in relation to the beneficiary's body surface area.

Definitions

AllogeneicTransplantation of cells, tissues, or organs between genetically different individuals of the same species.

Flow CytometryLaboratory technique that quantifies cell populations and characteristics such as naïve T-cell counts.

HLA MatchingTesting to determine human leukocyte antigen compatibility between donor and recipient.

EPSDTEarly and Periodic Screening, Diagnostic, and Treatment requirement mandating coverage of medically necessary services for Medicaid beneficiaries under 21 when criteria met.