Safety, Tolerability, Pharmacokinetics, and Therapeutic Efficacy of SAR441344 in Primary Sjögren's Syndrome (pSjS)

Inclusion Criteria

• Participant must be 18 to 80 years of age inclusive, at the time of signing the informed consent.
• Diagnosis of pSjS according to the American College of Rheumatology/EULAR 2016 criteria at Screening.
• Disease duration since first diagnosis of pSjS ≤15 years based on medical history.
• Participants with moderate to severe disease activity set with ESSDAI total score ≥5, based on the following domains at Screening: glandular, articular, muscular, hematological, biological, and constitutional, lymphadenopathy.
• Seropositive for anti-Ro/SSA antibodies.
• IgG > lower limit of normal (ULN) at Screening.
• Stimulated salivary flow rate of ≥0.1 mL/min at Screening or Baseline.
• Body weight within 45 to 120 kg (inclusive) and body mass index within the range of 18.0 to 35.0 kg/m2 (inclusive) at Screening.
• Contraceptive use by men or women should be consistent with local regulations regarding the methods of contraception for those participating in clinical studies.
• Capable of giving signed informed consent.

Exclusion Criteria

• Any autoimmune disease (except pSjS and Hashimoto thyroiditis) with or without secondary SjS.
• History, clinical evidence, suspicion or significant risk for thromboembolic events, as well as myocardial infarction, stroke, and/or antiphospholipid syndrome and any participants requiring antithrombotic treatment.
• Active life threatening or organ threatening complications of pSjS disease at the time of Screening based on treating physician evaluation including but not restricted to:
• Vasculitis with renal, digestive, cardiac, pulmonary, or CNS involvement characterized as severe,
• Active central nervous system (CNS) or peripheral nervous system (PNS) involvement requiring high dose steroids,
• Severe renal involvement defined by objective measures,
• Lymphoma.
• Cardiac heart failure Stage III or IV according to the New York Heart Association.
• Severe pulmonary impairment documented by an abnormal pulmonary function test.
• Serious systemic viral, bacterial or fungal infection (eg, pneumonia, pyelonephritis), infection requiring hospitalization or IV antibiotics or significant chronic viral (including history of recurrent or active herpes zoster), bacterial, or fungal infection (eg, osteomyelitis) 30 days before and during Screening.
• Participants with a history of invasive opportunistic infections, such as, but not limited to histoplasmosis, listeriosis, coccidioidomycosis, candidiasis, pneumocystis jirovecii, and aspergillosis, regardless of resolution.
• Evidence of active or latent tuberculosis (TB) as documented by medical history (eg, chest X rays) and examination, and TB testing: A positive or 2 indeterminate QuantiFERON® TB Gold tests at Screening (regardless of prior treatment status).
• Evidence of any clinically significant, severe or unstable, acute or chronically progressive, uncontrolled infection or medical condition (eg, cerebral, cardiac, pulmonary, renal, hepatic, gastrointestinal, neurologic, or any known immune deficiency) or previous, active or pending surgical disorder, or any condition that may affect participant safety in the judgment of the Investigator (including vaccinations which are not updated based on local regulation).
• History or presence of diseases which exclude diagnosis of SjS as per the American College of Rheumatology/EULAR 2016 criteria including, but not limited to, sarcoidosis, amyloidosis, graft-versus-host disease, IgG4 related disease, and history of head and neck radiation treatment.
• History of systemic hypersensitivity reaction or significant allergies, other than localized injection site reaction, to any humanized monoclonal antibody.
• Clinically significant multiple or severe drug allergies, intolerance to topical corticosteroids, or severe post treatment hypersensitivity reactions (including, but not limited to, erythema multiforme major, linear IgA dermatosis, toxic epidermal necrolysis, and exfoliative dermatitis).
• An