An Efficacy and Safety Study of Injectable Ravagalimab to Assess Change in EULAR Sjogren's Syndrome Disease Activity Index (ESSDAI) in Adult Participants With Moderately to Severely Active Primary Sjogren's Syndrome (pSS)

Sjogren's syndrome (SS) is a chronic, multisystem autoimmune disease characterized by lacrimal and salivary gland inflammation, with resultant dryness of the eyes and mouth and occasional glandular enlargement. In addition, a variety of systemic manifestations may occur; including fatigue, musculoskeletal symptoms, rashes, and internal organ (e.g., pulmonary, renal, hepatic, and neurologic) disease. Sjogren's syndrome may occur in isolation, primary Sjogren's syndrome (pSS), or in a secondary form, often associated with rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), or systemic sclerosis. Ravagalimab is an investigational drug being developed to help treat patients with inflammatory diseases like SS. This study will evaluate how well ravagalimab works within the body and how safe it is in patients with primary SS (pSS).

Ravagalimab, a potent CD40 antagonist is an investigational drug being developed for the treatment of Sjogren's syndrome (SS). This study is "double-blinded", which means that neither the trial participants nor the study doctors will know who will be given which study drug. Study doctors put the participants in 1 of 2 groups, called treatment arms. Each group receives a different treatment. There is a 1 in 2 chance that participants will be assigned to placebo. Participants 18-75 years of age with Sjogren's syndrome (SS) will be enrolled. Around 45 participants will be enrolled in the study in multiple sites within Netherlands.

Participants will receive ravagalimab intravenous (IV) loading dose or IV placebo at baseline followed by subcutaneous (SC) ravagalimab or matching placebo for 22 weeks.

There will be a higher treatment burden for participants in this trial compared to their standard of care. Participants will attend regular visits during the study at a hospital or clinic. The effect of the treatment will be checked by medical assessments, blood tests, labial gland (lip) biopsy, and checking for side effects and completing questionnaires.


Eligibility Criteria:
Inclusion Criteria:

* Primary Sjogren's syndrome (pSS) diagnosed according to the American College of Rheumatology (ACR)/European League Against Rheumatism (EULAR) 2016 Criteria.
* Lymphocyte focus score (local lymphocytic infiltrates) \>= 1 in sublabial salivary gland specimen. Subjects with sublabial salivary gland biopsy obtained 3 months prior to Screening and meeting this criterion will be eligible without a biopsy at Screening. Subjects without a sublabial salivary gland biopsy within 3 months of Screening will obtain a biopsy for a lymphocyte focus score at Screening.
* EULAR Sjogren's Syndrome Disease Activity Index (ESSDAI) \>= 5 at Screening.
* EULAR Sjogren's Syndrome Patient Reported Index (ESSPRI) \>= 6 at Screening.

Exclusion Criteria:

* History of clinically significant drug or alcohol abuse within the last 6 months.
* History of an allergic reaction or significant sensitivity to constituents of the study drug (and its excipients), the ingredients of Chinese hamster ovary cells and/or other products in the same class.