A Post-authorization Study to Describe the Safety and Efficacy of Emapalumab for the Treatment of pHLH in Treatment Experienced Chinese Patients

An Open Label, Single Arm, Multi-Centre, Post-authorization Study to Describe the Safety and Efficacy of Emapalumab for the Treatment of Primary Hemophagocytic Lymphohistiocytosis in Treatment Experienced Chinese Patients

The goal of this post-authorization study is to describe safety and efficacy of emapalumab in treatment experienced Chinese patients with pHLH.

Study Overview

• Status: Completed
• Conditions: Primary Hemophagocytic Lymphohistiocytosis
• Intervention / Treatment: Drug: Emapalumab-Lzsg 5 MG/ML [Gamifant]

Detailed Description

This is an open-label, multi center, single arm, post-authorization study aiming to describe safety and efficacy of emapalumab in treatment experienced Chinese patients with confirmed or suspected primary hemophagocytic lymphohistiocytosis (pHLH). The main objectives of the study are to collect safety and efficacy data on emapalumab in treatment experienced Chinese pHLH patients

• Study Type: Interventional
• Enrollment (Actual): 13
• Phase: Phase 4

Contacts and Locations

Study Locations

• China
  • Beijing, China
    • Swedish Orphan Biovitrum Research site
  • Chongqing, China
    • Swedish Orphan Biovitrum Research site
  • Guangzhou, China
    • Swedish Orphan Biovitrum Research site
  • Nanjing, China
    • Swedish Orphan Biovitrum Research site
  • Zhengzhou, China
    • Swedish Orphan Biovitrum Research site
  • Fudan
    • Shanghai, Fudan, China
      • Swedish Orphan Biovitrum Research site
  • Xicheng
    • Beijing, Xicheng, China
      • Swedish Orphan Biovitrum Research site

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Male and female HLH patients of any age.

2. Patients diagnosed with confirmed or suspected pHLH, based on; a molecular diagnosis or familial history consistent with pHLH or fulfilment of HLH-2004 diagnostic criteria, i.e., five out of eight of the criteria below:

   • Fever
   • Splenomegaly
   • Cytopenias affecting 2 of 3 lineages in the peripheral blood (hemoglobin <90 g/L; platelets <100 x 109/L; neutrophils <1 x 109/L)
   • Hypertriglyceridemia (fasting triglycerides ≥3 mmol/L or ≥265 mg/dL) and/or hypofibrinogenemia (≤1.5 g/L)
   • Hemophagocytosis in bone marrow, spleen, or lymph nodes, with no evidence of malignancy.
   • Low or absent NK-cell activity
   • Ferritin ≥500 μg/L
   • Soluble CD25 (sCD25; i.e., soluble IL-2 receptor) ≥2400 U/mL
3. Presence of active HLH disease as assessed by the investigator.

4. Patients must fulfil one of the following criteria as assessed by the investigator:

   • Having not responded to previous conventional treatment of HLH
   • Having not achieved a satisfactory response to previous conventional treatment of HLH or worsened
   • Having reactivated HLH
   • Showing intolerance to previous conventional treatment of HLH At the time of enrollment, eligible patients might still be receiving treatment (induction or maintenance) or might have already discontinued it.
5. Expectation of survival beyond 1 week as judged by the investigator.
6. Patient has expectation of proceeding to HSCT
7. Informed consent signed by the patient (as required by local law), or by the patient's legally authorized representative(s) with the assent of patients who are legally capable of providing it, as applicable.
8. Willing to use highly effective methods of contraception from study drug initiation to 6 months after the last dose of study drug, if female and of childbearing potential.

Exclusion Criteria:

1. Diagnosis of secondary HLH consequent to a proven rheumatic, metabolic or neoplastic disease.
2. Active mycobacteria, Histoplasma capsulatum, Salmonella, or Leishmania infections.
3. Evidence of latent tuberculosis.
4. Presence of malignancy.
5. Existence of any severe co-morbidity or any other medical condition which, in the opinion of the investigator, makes the patient unsuitable for the treatment
6. History of hypersensitivity or allergy to any component of the study regimen (e.g., polysorbate).
7. Receipt of a Bacillus Calmette-Guérin (BCG) vaccine within 12 weeks prior to Screening.
8. Receipt of a live or attenuated live (other than BCG) vaccine within 4 weeks prior to Screening.
9. Pregnant or lactating female patients.
10. Enrollment in another concurrent clinical interventional study, or intake of an IMP, within three months prior to inclusion in this study
11. Any condition or circumstance that in the opinion of the Investigator may make the patient unlikely to complete the study or comply with study procedures or requirements.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: emapalumab; emapalumab solution for infusion twice weekly at a starting dose of 1 mg/kg	Drug: Emapalumab-Lzsg 5 MG/ML [Gamifant]; iv; Other Names: Gamifant

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Permanent Discontinuation of Study Drug Due to Emapalumab-related Adverse Event	Number of participants permanently discontinuation of study drug due to emapalumab-related adverse event as judged by Investigator, until conditioning for hematopoietic stem cell transplant (HSCT), likely within 6 months from first dose	Until conditioning for hematopoietic stem cell transplant (HSCT), likely within 6 months from first dose

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Overall Response	Number of participants with an overall response i.e., achievement of either Complete Response or Partial Response or HLH Improvement, at end of treatment or week 8 (whichever occurs earlier).	End of treatment or week 8 (whichever occurs earlier)
Time to First Overall Response	Time to first overall response from first dose of study drug to the first achievement of response (Complete Response, Partial Response, or HLH Improvement)	End of treatment, likely within 6 months from first dose
Cumulative Duration of Response	Cumulative duration of response is defined as total time in response from the first achievement of an Overall Response until EOT. For patients who achieve a response, lost that response, and then achieve it subsequently, the total time in response is calculated by adding together these separate periods in response.	End of treatment, likely within 6 months from first dose
Ability to Reduce Glucocorticoids by 50% or More	Number of participants able to reduce glucocorticoids by 50% or more of the baseline dose at any time point of the treatment period	End of treatment, likely within 6 months from first dose
Investigator Assessed Response	Investigator's assessment of how patient responds to treatment and rated as complete response, partial response, or no response	End of treatment
Survival	Number of participants surviving to start of HSCT conditioning and Number of participants that underwent HSCT surviving after HSCT to end of study	End of study (1 year)

Collaborators and Investigators

• Sponsor: Swedish Orphan Biovitrum
• Investigators: Principal Investigator: Rui Zhang, MD, Prof, Beijing Children's Hospital

Study record dates

Study Major Dates

• Study Start (Actual): February 3, 2023
• Primary Completion (Actual): February 21, 2025
• Study Completion (Actual): August 8, 2025

Study Registration Dates

• First Submitted: February 13, 2023
• First Submitted That Met QC Criteria: February 23, 2023
• First Posted (Actual): February 24, 2023

Study Record Updates

• Last Update Posted (Actual): March 13, 2026
• Last Update Submitted That Met QC Criteria: March 12, 2026
• Last Verified: September 1, 2025

More Information

Terms related to this study

• Keywords: pHLH
• Additional Relevant MeSH Terms: Lymphatic Diseases; Histiocytosis, Non-Langerhans-Cell; Histiocytosis; Hemic and Lymphatic Diseases; Lymphohistiocytosis, Hemophagocytic; Emapalumab
• Other Study ID Numbers: Sobi.emapalumab-104

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No