CurrentMass General Brigham Health PlanPolicy 075

Casgevy (exagamglogene autotemcel) gene therapy — coverage criteria for SCD and transfusion‑dependent beta‑thalassemia

Policy governs prior authorization and medical necessity criteria for Casgevy (exagamglogene autotemcel) for members with sickle cell disease (SCD) or transfusion-dependent beta-thalassemia (TDT) for Mass General Brigham Health Plan products, including Commercial, MassHealth, and Medicare Advantage where noted.

Policy Summary

PayerMass General Brigham Health Plan

PolicyCasgevy (exagamglogene autotemcel) gene therapy — coverage criteria for SCD and transfusion‑dependent beta‑thalassemia

Policy CodePolicy 075

Change TypeMaterial updates to indications, medical necessity criteria, codes, and MassHealth prior authorization process

Effective DateApr 1, 2024

Next Review DateApr 1, 2025

Key ActionSubmit prior authorization with documented age, diagnosis confirmation, laboratory evaluation, treatment site, and required transfusion or hydroxyurea history per criteria.

SourceLink

POLICY UPDATE CHANGES

FDA-approved indications and medical necessity criteria updated; Codes and code list updated.

MassHealth variation updated to include a new prior authorization process.

Summary of evidence added describing pivotal trials CLIMB SCD-121 and CLIMB THAL-111 and long-term follow-up results.

12+FDA-approved minimum age for indications

>=4/24moSCD VOCs threshold

>=100 ml/kg/yrTDT transfusion requirement

Trek Health ingests and normalizes Transparency in Coverage data and payer policy updates to give provider organizations a clear view of how commercial reimbursement behaves across markets, payers, and services. Our platform transforms raw payer disclosures into structured intelligence that supports contract evaluation, payer negotiations, and service line strategy. By combining market benchmarks with ongoing policy visibility, Trek helps teams identify variability, risk, and opportunity in commercial reimbursement. The result is faster insight, stronger negotiating positions, and more informed financial decisions.

Medical Necessity and Coverage Criteria

Initial therapy / medical necessity

Covered when ALL of the following general eligibility criteria are met and when ALL criteria for either SCD or TDT are met:

General eligibility: Member is ≥12 years of age; laboratory evaluation without evidence of advanced liver disease; treatment will be administered in a qualified treatment facility as per product website; no active/uncontrolled infections, including HIV, HBV, and HCV.

General baseline requirements per policy

Disease-specific: Sickle Cell Disease (SCD)

SCD clinical requirements: Genetic test confirms SCD; at least 4 vaso-occlusive crises (VOCs)/vaso-occlusive events (VOEs) in the past 24 months (including but not limited to acute chest syndrome, acute splenic/hepatic sequestration, or priapism >2 hours requiring medical visit); and one of the following: inadequate response to hydroxyurea after ≥3 months with good adherence based on pharmacy claims or provider documentation, or adverse reaction/contraindication to hydroxyurea, or chronic transfusion therapy without hydroxyurea for primary or secondary stroke prevention.>=4 VOCs/24 months
Includes hydroxyurea trial/adherence requirement

Disease-specific: Transfusion-dependent Beta-Thalassemia (TDT)

TDT clinical requirements: Diagnosis of transfusion-dependent beta-thalassemia requiring at least 100 ml/kg body weight (or ≥10 units packed RBCs) per year for the previous two years to maintain target hemoglobin levels; and no evidence of severe iron overload.>=100 ml/kg/yr or >=10 units/yr
Transfusion dependence documented for prior 2 years

Casgevy is not covered for members with a history of hematopoietic stem cell transplant (HSCT) or for those with prior gene therapy for sickle cell disease. Requests for treatment that document either prior HSCT or prior gene therapy will be excluded from coverage.

Casgevy (exagamglogene autotemcel) is considered experimental/investigational and not covered for all indications other than sickle cell disease (SCD) and transfusion-dependent beta-thalassemia (TDT). Requests for use outside these FDA‑approved indications will be denied as not medically necessary.

Procedure and Drug Codes; Key Criteria Values

Applicable procedure and drug codes (informational)mixed

38206	Blood-derived hematopoietic progenitor cell harvesting for transplantation, per collection; autologous
38207	Transplant preparation of hematopoietic progenitor cells; cryopreservation and storage
38208	Transplant preparation of hematopoietic progenitor cells; thawing of previously frozen harvest, without washing per donor
38241	Hematopoietic progenitor cell (HPC); autologous transplantation
J3392	INJECTION, EXAGAMGLOGENE AUTOTEMCEL, PER TREATMENT

TDT transfusion requirement — key thresholds

TDT transfusion volume thresholdAt least 100 ml/kg body weight per year (or ≥10 units packed RBCs per year) documented for the previous two years to maintain target hemoglobin levels.

Duration requirementTransfusion dependence must be documented for the prior two years.

Iron overload assessmentNo evidence of severe iron overload required alongside transfusion dependence.

SCD vaso-occlusive crisis (VOC) frequency threshold

VOC frequency thresholdAt least 4 vaso-occlusive crises (VOCs/VOEs) in the past 24 months (includes acute chest syndrome, acute splenic/hepatic sequestration, priapism >2 hours requiring medical visit).

Documentation of events

Prior Authorization, Documentation, and Operational Rules

Prior Authorization

Prior Authorization Required

Prior authorization is required for Casgevy (exagamglogene autotemcel) across Commercial, MassHealth, and Medicare Advantage as specified. For MassHealth ACO members, submit requests to the MassHealth Drug Utilization Review Program per Table 45: Beta Thalassemia / Myelodysplastic Syndrome and Sickle Cell Disease Agents.

Affected plans: Commercial, MassHealth, Medicare Advantage
MassHealth prior authorization variation: submit to MassHealth DUR Program (see Table 45)

Step Therapy

Step / Prior Therapy Requirements

Step/prior therapy requirements must be documented for Sickle Cell Disease (SCD) and Transfusion-dependent β-thalassemia (TDT) requests. For SCD: document genetic confirmation of SCD and treatment history showing inadequate response to hydroxyurea after ≥3 months with good adherence, or documentation of contraindication/adverse reaction to hydroxyurea, or chronic transfusion therapy without hydroxyurea for stroke prevention. Also document clinical history of vaso-occlusive complications (e.g., ≥4 VOC/VOE in past 24 months, acute chest syndrome, splenic/hepatic sequestration, prolonged priapism) or acute pain events requiring medical facility visits. For TDT: document diagnosis of transfusion-dependence requiring ≥100 ml/kg/year (or ≥10 units packed RBCs/year) for the prior two years to maintain target hemoglobin, and no evidence of severe iron overload.

Clinical Background and Therapy Description

Casgevy (exagamglogene autotemcel, also known as exa‑cel) is an autologous CD34+ hematopoietic stem cell gene‑editing therapy that uses CRISPR/Cas9 to target the erythroid‑specific BCL11A enhancer and increase fetal hemoglobin (HbF) expression in erythroid cells. It is FDA‑approved for patients aged 12 years and older with sickle cell disease with recurrent vaso‑occlusive crises and for transfusion‑dependent beta‑thalassemia; pivotal single‑arm CLIMB trials demonstrated substantial clinical benefits including resolution of VOCs and transfusion independence in most treated patients.

Key Terms and Abbreviations

Casgevy (exagamglogene autotemcel) — definition and mechanism

Product definitionCasgevy (exagamglogene autotemcel) is an autologous hematopoietic stem cell–based gene therapy in which patient CD34+ cells are edited using CRISPR/Cas9 targeting the erythroid‑specific BCL11A enhancer to increase fetal hemoglobin expression in erythroid cells.

Therapeutic approachAutologous CD34+ hematopoietic stem cells are gene‑edited ex vivo and then returned to the patient after myeloablative conditioning to produce durable HbF induction.

Intended indicationsFDA‑approved for treatment of severe sickle cell disease (SCD) and transfusion‑dependent beta‑thalassemia (TDT) in patients aged ≥12 years.

exa‑cel — trial abbreviation

Clinical trial shorthandexa‑cel is the abbreviated name used for exagamglogene autotemcel in clinical trial reports (e.g., CLIMB SCD‑121, CLIMB THAL‑111).

Policy Summary

PayerMass General Brigham Health Plan

PolicyCasgevy (exagamglogene autotemcel) gene therapy — coverage criteria for SCD and transfusion‑dependent beta‑thalassemia

Policy CodePolicy 075

Change TypeMaterial updates to indications, medical necessity criteria, codes, and MassHealth prior authorization process

Effective DateApr 1, 2024

Next Review DateApr 1, 2025

Key ActionSubmit prior authorization with documented age, diagnosis confirmation, laboratory evaluation, treatment site, and required transfusion or hydroxyurea history per criteria.

SourceLink

On This Page

Each qualifying VOC must be an acute pain event requiring a visit to a medical facility for pain medications or RBC transfusion.

Additional clinical requirementOne of: inadequate response to hydroxyurea after ≥3 months with good adherence; adverse reaction/contraindication to hydroxyurea; or chronic transfusion therapy without hydroxyurea for stroke prevention.

SCD: inadequate response to hydroxyurea ≥3 months with documented adherence OR adverse reaction/contraindication to hydroxyurea OR chronic transfusion therapy without hydroxyurea for stroke prevention
SCD: clinical history including ≥4 VOC/VOE in past 24 months or other severe SCD complications
TDT: transfusion requirement ≥100 ml/kg/year (or ≥10 units/year) for prior 2 years; document absence of severe iron overload

Documentation Required

Document the following with the authorization request: member age (≥12 years), genetic confirmation for SCD when applicable, laboratory evaluation showing no advanced liver disease, treatment location (qualified treatment facility), absence of active/uncontrolled infections (including HIV, HBV, HCV), and prior treatment history supporting step-therapy requirements (hydroxyurea use/adherence documentation or contraindication; transfusion history for TDT).

Age: ≥12 years
Laboratory: no advanced liver disease
Treatment site: qualified treatment facility per product guidance
Infections: no active/uncontrolled infections (HIV, HBV, HCV)
Prior therapy: hydroxyurea treatment details or contraindication; transfusion records for TDT

Denial Risk

Denial Risk / Operational Risks

Requests that lack the required documentation or do not meet general eligibility (e.g., age <12, evidence of advanced liver disease, active/uncontrolled infection, history of prior HSCT or prior gene therapy for SCD, or failure to meet the SCD/TDT-specific criteria) may be denied. Additionally, certain procedure/coding constraints apply per payer (see code list).

Denial triggers include: missing genetic confirmation for SCD, inadequate prior therapy documentation, evidence of advanced liver disease, active/uncontrolled infection, age <12, history of HSCT or prior gene therapy for SCD
Coding note: relevant codes include 38206, 38207, 38208, 38241, and J3392 (applies to Commercial and MassHealth)

Trial contextPivotal CLIMB trials (CLIMB SCD‑121 and CLIMB THAL‑111) used the term exa‑cel to report outcomes in patients aged 12–35 with severe SCD or TDT.

Regulatory noteRegulatory and published reports reference exa‑cel when describing the investigational/approved product Casgevy in trial data and follow‑up studies.