Clinical Drug Experience Knowledgebase

Hemophagocytic Lymphohistiocytosis

OBJECTIVES:

Primary

Provide and evaluate revised induction and maintenance therapy comprising etoposide, dexamethasone, and cyclosporine, in terms of achieving and maintaining an acceptable clinical condition in order to perform a curative allogeneic hematopoietic stem cell transplantation (AHSCT), in patients with primary inherited or severe and persistent secondary hemophagocytic lymphohistiocytosis (HLH).
Evaluate and improve the outcome of AHSCT with various types of donors.
Determine the prognostic importance of the state of remission at the time of AHSCT.
Evaluate the neurological complications, in terms of early neurological alterations and cerebrospinal fluid (CSF) findings, in patients treated with this regimen.

Secondary

Improve the understanding of the pathophysiology of HLH by conducting biological studies of genetics and cytotoxicity in these patients, including genotype-phenotype studies and the prognostic value of natural killer (NK) cell activity subtyping.

OUTLINE: This is a multicenter study.

Induction therapy (weeks 1-8): Patients receive etoposide IV over 1-3 hours twice weekly in weeks 1 and 2 and then once weekly in weeks 3-8. Patients also receive dexamethasone IV or orally once daily and cyclosporine IV or orally twice daily in weeks 1-8. Patients with clinically evident, progressive neurological symptoms or an abnormal cerebrospinal fluid (CSF) (cell count and protein) that has not improved after 2 weeks of induction therapy undergo intrathecal therapy comprising methotrexate and hydrocortisone once weekly in weeks 3-6.

Patients are evaluated after 8 weeks of induction therapy. Patients with primary (i.e., familial) hemophagocytic lymphohistiocytosis (HLH) or genetic evidence of HLH proceed to maintenance therapy. Patients with severe and persistent secondary (i.e., nonfamilial) HLH and no genetic evidence of HLH proceed to maintenance therapy only if their disease is still active after induction therapy. Patients with nonfamilial HLH and no genetic evidence of HLH who have achieved complete remission (CR) discontinue treatment. If their disease reactivates, they may then proceed to allogeneic hematopoietic stem cell transplantation (AHSCT).

Maintenance therapy (weeks 9-40): Patients receive dexamethasone IV on days 1-3 in weeks 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, and 40; etoposide IV over 1-3 hours once in weeks 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, and 39; and cyclosporine IV or orally twice daily in weeks 9-40.

After completion of maintenance therapy, patients with primary (i.e., familial) HLH, severe and persistent secondary (i.e., nonfamilial) HLH, or reactivating disease proceed to AHSCT. Patients with nonfamilial HLH who have completed maintenance therapy, but do not go on to receive AHSCT, may be recommended for additional maintenance therapy at the discretion of the treating physician.

AHSCT:

Preparative regimen: Patients receive a preparative regimen comprising busulfan orally or IV four times daily on days -8 to -5, etoposide IV over 6 hours on day -4, and cyclophosphamide IV over 1 hour on days -3 and -2. Patients who are undergoing unrelated AHSCT, also receive antithymocyte globulin (ATG) IV over 12 hours on days -3 to -1.
Transplantation: Patients undergo AHSCT on day 0.
Graft-versus-host disease prophylaxis: Beginning on day -1, patients receive cyclosporine IV continuously and then orally, when tolerated, once daily for 6-12 months. Patients also receive methotrexate* IV on days 1, 3, and 6.

NOTE: *As a substitute for methotrexate, patients may receive oral mycophenolate mofetil twice daily on days 0-40, followed by a taper and discontinuation.

Patients undergo periodic blood collection and bone marrow biopsies for biological studies.

After completion of study treatment, patients are followed periodically for up to 5 years.

PROJECTED ACCRUAL: A total of 288 patients will be accrued for this study.