Study of Daxdilimab (HZN-7734) for the Treatment of Systemic Lupus Erythematosus in an Open-label Extension Study

Study Overview
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Brief Summary
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A Phase 2, Open-Label Extension study to evaluate the long-term safety and tolerability of daxdilimab in participants with Systemic Lupus Erythematosus completing the treatment period of the RECAST SLE clinical study.

Detailed Description
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Approximately 156 participants will be enrolled to receive daxdilimab administered subcutaneously over 48 weeks. The maximum trial duration per participant is approximately 56 weeks, including the 48 weeks for the open-label treatment period where participants will receive daxdilimab and approximately 8 weeks for the follow-up period. Safety evaluations will be performed regularly throughout the course of the study.

Official Title
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An Open-Label Extension Study To Evaluate The Long- Term Safety And Tolerability Of Daxdilimab (Hzn-7734) In Subjects With Systemic Lupus Erythematosus

Conditions
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Systemic Lupus Erythematosus

Intervention / Treatment
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* Biological: Daxdilimab


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Willing and able to understand and provide written informed consent. Must have completed the treatment period in the RECAST SLE study. Women of childbearing potential must have a negative urine pregnancy test on Day 1. Nonsterilized male subjects who are sexually active with a woman partner of childbearing potential must agree to use a condom with spermicide from Day 1 and until 3 months (approximately 5 half-lives) after receipt of the last dose. Exclusion Criteria: Any condition or change during the RECAST SLE study that in the opinion of the Investigator or the Sponsor would interfere with evaluation and interpretation of subject safety or alter the risk-benefit associated with IP administration. Participation in another clinical study with an IP during the RECAST SLE study period. Planned elective surgeries that in the opinion of the Investigator or the Sponsor would interfere with evaluation and interpretation of subject safety. Any herpes zoster, cytomegalovirus, or Epstein-Barr virus infection that was not completely resolved prior to Visit 1. Clinically significant active infection at Visit 1, in the opinion of the Investigator. Pregnant or lactating females.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 72 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Daxdilimab<br>Daxdilimab injections over a total of 48 weeks. | Biological: Daxdilimab<br>* Daxdilimab will be administered subcutaneously as two injections for each dose.<br>* Other names: HZN-7734;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Incidence of treatment-emergent adverse events (TEAEs), treatment-emergent serious adverse events (TESAEs), and treatment-emergent adverse events of special interest (AESIs). |  | Day 1 to Week 48 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change from baseline in in plasmacytoid dendritic cells (pDCs). |  | Day 1 to Week 48 | 
| Anti-drug antibody (ADA) rate. |  | Day 1 to Week 48 |