A Study of the Effect of XmAb®5871 in Patients With Systemic Lupus Erythematosus

Study Overview
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Brief Summary
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The purpose of this study is to determine the ability of XmAb5871 to maintain Systemic Lupus Erythematosus (SLE) disease activity improvement achieved by a brief course of disease-suppressing steroid therapy

Official Title
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A Randomized, Double-Blinded, Placebo-Controlled Study of the Effect of XmAb®5871 on Systemic Lupus Erythematosus Disease Activity

Conditions
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Systemic Lupus Erythematosus

Intervention / Treatment
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* Biological: XmAb5871
* Biological: Placebo to match XmAb5871


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients with a diagnosis of SLE as defined by the ACR criteria Patients have a history of a (+) ANA, (+) ENA or a (+) anti-dsDNA serology documented within one year prior to randomization Investigator has assessed the patient and in their judgment, the SLE disease activity is not organ threatening Both investigator and patient agree that it is acceptable to discontinue their current immunosuppressant SLE medications and receive a brief course of IM steroid therapy If patients are on oral steroids, they must be on the equivalent of ≤15 mg/day of prednisone to enter screening, and must be able to taper to ≤10 mg/day by randomization Exclusion Criteria: History or evidence of a clinically unstable/uncontrolled disorder, condition or disease, other than SLE that, in the opinion of the investigator would pose a risk to patient safety or interfere with the study evaluation, procedures or completion Patients who have organ threatening manifestations of SLE including active Class 3 or 4 lupus nephritis requiring induction or maintenance therapy or any other disorder for which stopping SLE therapy is contraindicated Active CNS lupus such as seizures or psychosis that in the opinion of the investigator would preclude participation Unstable hemolytic anemia or thrombocytopenia Patient is pregnant or breast feeding, or planning to become pregnant while participating in the study Use of any biologic therapy (including belimumab) within 6 months of randomization, or prior exposure to a monoclonal antibody directed to CD20 (such as rituximab) within 12 months of randomization

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 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
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Randomized (1:1, no stratification), Double-Blinded, Placebo-Controlled
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: XmAb5871<br>XmAb5871 administered by IV infusion for up to a total of 16 infusions | Biological: XmAb5871<br> <br> |
| Placebo Comparator: Placebo<br>Placebo to match XmA5871 administered by IV infusion for up to a total of 16 infusions | Biological: Placebo to match XmAb5871<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Percentage of Patients Without Loss of Systemic Lupus Erythematosus Disease Activity Improvement on Day 225 | Landmark proportion of patients without loss of systemic lupus erythematosus disease activity improvement on Day 225 | Day 225 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Percentage of Patients Without Loss of Systemic Lupus Erythematosus Disease Activity Improvement on Day 169 | Landmark proportion of patients without loss of systemic lupus erythematosus disease activity improvement on Day 169 | Day 169 | 
| Time to Loss of Systemic Lupus Erythematosus Disease Activity Improvement Achieved by a Short Period of IM Steroid Therapy in SLE Patients | Loss of improvement was defined as worsening of disease activity that in the opinion of the principal investigator requires a change in treatment (exclusive of a decrease in oral steroids) AND one of: SELENA- SLEDAI increase of >=4 points from maximal improvement OR Worsening of at least 1 BILAG A or B score OR New BILAG A or B score. | From the date of randomization until the date of loss of Systemic Lupus Erythematosus Disease Activity Improvement, or the date of the final efficacy assessment, up to 239 days. |