Alemtuzumab or Tocilizumab in Combination With Etoposide and Dexamethasone for the Treatment of Adult Patients With Hemophagocytic Lymphohistiocytosis

"Group 1 and 2 Induction Phase: Alemtuzumab total dose of 1.0 mg/kg subcutaneously or by vein over 4 days (days 1-4) during the 8 week induction phase. Day 1 0.1 mg/kg, Day 2 0.3 mg/kg, Day 3 0.3 mg/kg, Day 4 0.3 mg/kg.~Group 1 Maintenance Phase: 0.2 mg/kg once every 4 weeks for 6 weeks."

"Induction Phase: 150 mg/m2 given by vein once a week for 8 weeks.~Maintenance Phase: Participants who have evidence of refractory disease or budding relapse during the maintenance phase may revert back to receiving Etoposide."

"Induction Phase: 10 mg/m2 for 1 week followed by Dexamethasone 5 mg/m2 for 2 weeks followed by Dexamethasone 2.5 mg/m2 for 2 weeks followed by Dexamethasone 1.25 mg/m2 for 2 weeks.~Maintenance Phase: 1.25 mg/m2 by mouth three times a week for 16 weeks."

Participants with central nervous system involvement receive intrathecal methotrexate 12 mg once a week for 5 weeks during the Induction Phase.

If participant responds to study drugs, they will receive a phone call by study staff every 3 - 6 months for up to 5 years after completion of treatment. Each call will last about 5-10 minutes.

Induction Phase: Tocilizumab at 4 to 8 mg/kg by vein. Day 1 0.1 mg/kg,Day 2 0.3 mg/kg, Day 3 0.3 mg/kg, Day 4 0.3 mg/kg.