Texas Medicaid Prior Authorization Criteria for Emapalumab-Lzsg (Gamifant)

Date: October 8, 2025

Attention: All Providers

Effective date: October 1, 2025

Call to action: Effective for dates of service on or after October 1, 2025, providers must meet updated prior authorization requirements for emapalumab-lzsg (Gamifant) (procedure code J9210).

Emapalumab-lzsg (Gamifant) is an interferon gamma (IFNy)-blocking antibody that is indicated for the treatment of the following:

• Primary hemophagocytic lymphohistiocytosis (HLH) in patients who have refractory, recurrent, or progressive disease or intolerance of conventional HLH therapy
• HLH or macrophage activation syndrome (MAS) in patients who have known or suspected Still’s disease (including systemic juvenile idiopathic arthritis [sJIA]) and an inadequate response to or intolerance of glucocorticoids or recurrent MAS

Authorization Requirements

Texas Medicaid will approve prior authorization requests for up to six months of initial therapy if the patient has one of the diagnoses listed below:

• Primary HLH (diagnosis code D761), diagnosed based on one of the following:
  • Genetic mutation of the gene known to cause primary HLH (e.g., PRF1, UNC13D, STX11, or STXBP2) or a family history consistent with primary HLH
  • Confirmation of at least five of the following criteria:
    • Fever ≥ 101.3 °F
    • Splenomegaly
    • Cytopenia defined by at least two of the following: Hemoglobin < 9 g/dl, platelet count < 100 x 10⁹ /L, or neutrophils < 1 x 10⁹
    • Fasting triglycerides > 265 mg/dl or fibrinogen ≤ 1.5 g/L
    • Hemophagocytosis in the liver, bone marrow, spleen, or lymph node
    • Low or absent natural killer (NK) cell activity
    • Serum ferritin concentration ≥ 500 mg/L
    • High plasma concentration of soluble CD25 (i.e., soluble interleukin-2 receptor) > 2,400 U/mL
• HLH or MAS in Still’s disease, diagnosed based on the following:
  • A diagnosis of HLH along with a confirmed or suspected diagnosis of systemic juvenile idiopathic arthritis or adult onset of Still’s disease
  • A diagnosis of active MAS with ferritin level greater than 684 ng/mL and any of two of the four laboratory criteria listed below:
    • Platelet count ≤ 181 x 10⁹/L
    • Aspartate aminotransferase (AST) > 48 U/L
    • Triglycerides > 156 mg/dL
    • Fibrinogen levels ≤ 360 mg/dL
• An inadequate response to high-dose IV glucocorticoids
• No active infections caused by specific pathogens favored by IFNy neutralizations (such as mycobacteria and Histoplasma capsulatum).

Providers must submit prior authorization requests for procedure code J9210 with one or more of the following diagnosis codes:

Renewal or Continuation Therapy

Prior authorization requests for renewal or continuation therapy with emapalumab-lzsg (Gamifant) must include documentation that the patient:

• Continues to meet the initial approval criteria.
• Continues to require emapalumab-lzsg (Gamifant) as HLA treatment.

Texas Medicaid will not approve prior authorization for renewal or continuation therapy after the initiation of hematopoietic stem cell transplant (HSCT) or if the treatment for HLH or MAS becomes unnecessary.

Next step for providers: Providers should share this communication with their staff.

If you have any questions, please email Provider Relations at providerrelations@texaschildrens.org. 

For access to all provider alerts: www.texaschildrenshealthplan.org/provideralerts.