WHA

Gamifant (emapalumab-lzsg)

Indications for Prior Authorization

Gamifant (emapalumab-lzsg)
  • For diagnosis of Primary Hemophagocytic Lymphohistiocytosis (HLH)
    Indicated for the treatment of adult and pediatric (newborn and older) patients with primary HLH with refractory, recurrent or progressive disease or intolerance with conventional HLH therapy.

  • For diagnosis of Hemophagocytic Lymphohistiocytosis (HLH)/Macrophage Activation Syndrome (MAS) in Still’s disease
    Indicated for the treatment of adult and pediatric (newborn and older) patients with HLH/MAS in known or suspected Still’s disease, including systemic Juvenile Idiopathic Arthritis (sJIA), with an inadequate response or intolerance to glucocorticoids, or with recurrent MAS.

Criteria

Gamifant

Prior Authorization (Initial Authorization)

Length of Approval: 6 Months [A]
For diagnosis of Primary Hemophagocytic Lymphohistiocytosis (HLH)

  • Diagnosis of primary hemophagocytic lymphohistiocytosis (HLH)
    • AND
  • One of the following:
    • Disease is one of the following:
      • Refractory
      • Recurrent
      • Progressive
      OR
    • Trial and failure, contraindication, or intolerance to conventional HLH therapy (e.g., etoposide, dexamethasone, cyclosporine A, intrathecal methotrexate)
    AND
  • Prescribed by or in consultation with a hematologist/oncologist
    • AND
  • Patient has not received hematopoietic stem cell transplantation (HSCT)
Gamifant

Prior Authorization (Reauthorization)

Length of Approval: 6 Months [A]
For diagnosis of Primary Hemophagocytic Lymphohistiocytosis (HLH)

  • Patient demonstrates positive clinical response to therapy (e.g., improvement in hemoglobin/lymphocyte/platelet counts, afebrile, normalization of inflammatory factors/markers)
    • AND
  • Patient has not received HSCT
Gamifant

Prior Authorization (Initial Authorization)

Length of Approval: 6 Months [B]
For diagnosis of Hemophagocytic Lymphohistiocytosis (HLH)/Macrophage Activation Syndrome (MAS) in Still’s disease

  • Both of the following:
    • Diagnosis of active hemophagocytic lymphohistiocytosis (HLH)/macrophage activation syndrome (MAS)
    • Disease occurs in known or suspected Still’s disease [e.g., systemic Juvenile Idiopathic Arthritis (sJIA), adult onset Still’s disease (AOSD)] [C]
    AND
  • One of the following:
    • Trial and failure, contraindication, or intolerance to high-dose corticosteroids (e.g., methylprednisolone, prednisone) [D]
    • Patient experiences recurrent MAS
    AND
  • Prescribed by or in consultation with a rheumatologist/hematologist
Gamifant

Prior Authorization (Reauthorization)

Length of Approval: 6 Months [B]
For diagnosis of Hemophagocytic Lymphohistiocytosis (HLH)/Macrophage Activation Syndrome (MAS) in Still’s disease

  • Patient demonstrates positive clinical response to therapy (e.g., improvement in leukocyte/platelet counts, afebrile, normalization of inflammatory factors/markers)

  • Guideline ID
    GL-328192

  • Formulary
    Premium

  • Effective date
    Oct 1, 2025

  • P&T approval date

P & T Revisions

2025-07-28, 2025-02-17, 2024-01-26, 2023-09-29, 2023-01-15, 2022-02-18, 2021-09-27, 2021-05-19, 2021-02-03, 2020-02-19

  1. Gamifant Prescribing Information. Sobi Inc. Waltham, MA. June 2025.
  2. Per clinical consult with a pediatric hematologist/oncologist, January 18, 2019.
  3. Rosee PL, Horne A, Hines M, et al. Recommendations for the management of hemophagocytic lymphohistiocytosis in adults. Blood. 2019; 133(23):2465-2477.
  4. Swedish Orphan Biovitrum. Evaluate efficacy, safety and tolerability, PK and PD of emapalumab in children and adults With MAS in Still's or SLE (EMERALD). ClinicalTrials.gov identifier: NCT05001737. Updated June 11, 2025. Accessed July 17, 2025. https://clinicaltrials.gov/study/NCT05001737
  5. Swedish Orphan Biovitrum. A study to investigate the safety and efficacy of emapalumab, an anti-IFN-gamma mAb in patients with systemic juvenile idiopathic arthritis (sJIA) or adult-onset Still's disease (AOSD) developing macrophage activation syndrome/​secondary HLH (MAS/​sHLH). ClinicalTrials.gov identifier: NCT03311854. Updated May 17, 2022. Accessed July 17, 2025. https://www.clinicaltrials.gov/study/NCT03311854
  6. De Benedetti F, Grom AA, Brogan P, et al. Macrophage activation syndrome (MAS) in systemic juvenile idiopathic arthritis (sJIA): Treatment with emapalumab, an anti-interferon gamma (IFNγ) monoclonal antibody. Blood. 2021; 138(S1):2058.
  7. Shakoory B, Geerlinks A, Wilejto, et al. The 2022 EULAR/ACR points to consider at the early stages of diagnosis and management of suspected haemophagocytic lymphohistiocytosis/macrophage activation syndrome (HLH/MAS). Ann Rheum Dis. 2023; 82(10):1271-1285.
  8. Fautrel B, Mitrovic S, De Matteis A, et al. EULAR/PReS recommendations for the diagnosis and management of Still's disease, comprising systemic juvenile idiopathic arthritis and adult-onset Still's disease. Ann Rheum Dis. 2024;83(12):1614-1627.
  9. Hines MR, Greenwood TVB, Beutel G, et al. Consensus-based guidelines for the recognition, diagnosis, and management of hemophagocytic lymphohistiocytosis in critically ill children and adults. Crit Care Med. 2022;50(5):860-872.
  1. Per clinical consultation, it is appropriate to limit authorization duration to no more than 6 months at a time, given that the ultimate goal in therapy is to receive HSCT and treatment with Gamifant should be viewed as bridge therapy to HSCT. Pivotal trial data duration was also less than 3 months. [2] Per label, Gamifant for primary HLH should only be administered until patient receives HSCT.
  2. Treatment duration of MAS should be individualized based on clinical response and laboratory markers. In the pivotal studies, Gamifant treatment regimen was adapted (i.e., increased frequency/dose, prolonged treatment beyond 4-week protocol) based on patient response. [3-6]
  3. MAS is a distinct form of secondary HLH that arises from systemic autoinflammatory or autoimmune conditions (e.g., Still’s disease, lupus, vasculitis), most commonly with rheumatologic conditions, that is managed differently from other secondary forms of HLH due to partial differences in pathogenesis. [3, 7]
  4. High dose corticosteroids are initial treatment for MAS, most commonly administered as intravenous pulses of methylprednisolone at 15 to 30 mg/kg/day, up to a maximum of 1 gram per infusion. For oral corticosteroids, high-dose corticosteroids are defined as 1 mg/kg/day of prednisone equivalent in adults and 2 mg/kg/day of prednisone equivalent in pediatrics. [8, 9]. In the pivotal studies, high dose intravenous corticosteroids were at least 2 mg/kg/day of prednisone equivalent, or at least 60 mg/day in pediatric patients 30 kg or higher or at least 1 gram/day in adults. [4, 5]
  • 2025-07-28: New criteria for new indication HLH/MAS in Still's.
  • 2025-02-17: 2025 Annual review: no criteria changes.
  • 2024-01-26: Annual Review, No criteria changes
  • 2023-09-29: Program update to standard reauthorization language. No changes to clinical intent.
  • 2023-01-15: Annual Review - no criteria changes
  • 2022-02-18: Annual review: no criteria changes.
  • 2021-09-27: Addition of EHB formulary to guideline, no changes to criteria
  • 2021-05-19: Addition of EHB formulary to guideline, no changes to criteria
  • 2021-02-03: Annual review: Added new product strength and updated reauthorization criteria.
  • 2020-02-19: Annual Review: Background updated.