Multiple Ascending Dose Study of MHS552 in Adults Participants With Systemic Lupus Erythematosus (SLE)

Inclusion Criteria

• •Fulfills the 2019 EULAR/American College of Rheumatology (ACR) classification criteria for SLE at least 3 months prior to and at screening.
• •Patients with mild or moderately active SLE (SLEDAI-2K between 3 and 10, inclusive) at screening. Patients with cutaneous lupus are eligible as long as they satisfy the criteria for systemic lupus.
• •Patients must be on stable dose(s) of at least one of the following medications, unless the medication has been discontinued due to intolerance, inadequate response, or patient/physician decision:
• •* steroid at a dose ≥ 5mg but \<30 mg of prednisone (or equivalent) per day,
• •* antimalarial (hydroxychloroquine/chloroquine/quinacrine) or thalidomide,
• •* disease modifying anti-rheumatic drugs (DMARDs):
• •* methotrexate (MTX),
• •* azathioprine (AZA),
• •* mizoribine,
• •* mycophenolate derivates. Steroid dose must be stable for at least 4 weeks prior to the first dosing. The dose of the other medications above must be stable for at least 12 weeks prior to the first dosing. If the patient is not on any medications listed above, they must have been off these medications for at least 12 weeks prior to dosing.
• •Systemic autoimmune disease other than lupus, which would interfere with participation in the study according to the Investigator's judgement. Treated, stable Hashimoto's thyroiditis is not exclusionary.
• •Any of the following abnormal laboratory values at Screening or pre-dose Day 1 assessment:
• •Hemoglobin levels below 8.0 g/dL at screening Eosinophil count \>700 mm3 or \>2 X Upper Limit of Normal (ULN), whichever is lower.
• •\- History of capillary leak syndrome (CLS).