Evaluation of the Safety and Efficacy of ELA026 in Participants With Secondary Hemophagocytic Lymphohistiocytosis

Evaluation of the Safety and Efficacy of ELA026 in Participants With Secondary Hemophagocytic Lymphohistiocytosis

A Phase 1b, Open-label, Single-arm, Multicenter Study to Evaluate the Safety, Efficacy, Pharmacokinetics and Pharmacodynamics of Multiple Doses of ELA026 in Participants With Secondary Hemophagocytic Lymphohistiocytosis (sHLH)

Hemophagocytic lymphohistiocytosis is a rare, aggressive and life-threatening syndrome of excessive immune activation. ELA026 is a fully human IgG1 SIRP-directed monoclonal antibody designed to reduce the myeloid and T cells driving the inflammation. The purpose of this study is to assess the safety, efficacy pharmacokinetics and pharmacodynamics of ELA026 in participants with secondary hemophagocytic lymphohistiocytosis.

This study is an open-label, single arm, multicenter interventional study, comprised of 4 cohorts; a dose escalating cohort (cohort 1) followed by 3 fixed dose cohorts (Cohorts 2-4). Newly diagnosed and previously treated participants with secondary hemophagocytic lymphohistiocytosis will be enrolled and treated over 12-weeks. Secondary hemophagocytic lymphohistiocytosis is the most common form of this disease and is typically associated with several other clinical conditions (eg, malignancy associated HLH (m-HLH), infection, or autoimmune disease).

Cohort 1: Single dose escalation up to 3.0 mg/kg IV or SC Cohorts 2-4: dose, route, and frequency of administration (IV or SC) to be determined

Incidence of adverse events (AEs) including dose-limiting toxicities (DLTs), serious adverse events (SAEs), deaths, AEs leading to withdrawal from study

Achievement of a complete response (CR), modified complete response (mCR), partial response (PR) or HLH improvement

Key Inclusion Criteria: All countries: ≥12 years at the time of HLH diagnosis (Cohort 1-4). US only: ≥12 years at the time of HLH diagnosis (Cohort 1-4) and 6 to <12 years at the time of HLH diagnosis (Cohorts 2-4) Treatment naïve OR; Relapsed refractory HLH. Participant is hospitalized with HLH confirmed criteria based on fulfilling 5 out of 8 HLH-2004 diagnostic criteria Key Exclusion Criteria: Known or previous treatment for primary HLH Any other significant concurrent, uncontrolled medical condition that in the opinion of the Investigator contraindicates participation in this study Hemopoietic Stem Cell Transplant (HSCT) within 100 days of the first dose of ELA026. All countries except US: Treatment with CAR T-Cell therapy within 3 months of the first dose of ELA026. US Only: Treatment with CAR T-Cell therapy allowed within 3 months of first dose. Ongoing administration of any investigational treatment (excluding dexamethasone) within 14 days prior to Screening or 5 drug half-lives, whichever is shorter Live or attenuated vaccine received within 6 weeks or bacille Calmette-Guerin (BCG) vaccine within 12 weeks prior to Screening