A Study for Long-term Follow-up of Hemophagocytic Lymphohistiocytosis (HLH) Participants Who Received Treatment With Emapalumab (NI-0501), an Anti-interferon Gamma Monoclonal Antibody

A Multicenter Study for the Long-term Follow-up of HLH Patients Who Received Treatment With NI-0501, an Anti-interferon Gamma Monoclonal Antibody

International, multicenter, long-term, follow-up study that will enrol HLH participants who have received emapalumab in previous clinical trials, in the context of the clinical development program for emapalumab or under compassionate use (CU).

The aim of this study is to monitor the long-term safety profile of emapalumab in participants who have previously received at least one dose of emapalumab, including survival time after the administration of emapalumab.

Moreover, the elimination profile of emapalumab and the immunogenicity will also be assessed.

Furthermore, safety, tolerability, efficacy, and pharmacokinetic (PK) profile of emapalumab will be closely monitored in the event that some participants, upon request of the treating physician, will receive emapalumab treatment in the follow-up study.

Inclusion Criteria:

• Having received at least one dose of emapalumab.
• Having signed the Informed Consent by the participant or the participant's legal representative(s), as applicable, with the assent of participant who are legally capable of providing it.

Exclusion Criteria:

• None