A Study to Evaluate the Safety, Tolerability and Efficacy of MHV370 in Participants With Sjogren's Syndrome (SjS) or Mixed Connective Tissue Disease (MCTD)

Exclusion Criteria

• •SjS and MCTD:
• •Prior use of B-cell depleting therapy within 6 months of baseline. For participants who received B-cell depleting therapy within 6 -12 months of baseline visit, B-cell count should be within normal range
• •Prior treatment with any of the following within 3 months of baseline: CTLA4-Fc Ig (abatacept), Anti-TNF mAb, Intravenous Ig, Plasmapheresis, i.v. or oral cyclophosphamide, i.v. or oral cyclosporine A
• •Screening CBC laboratory values as follows: Hemoglobin levels \< 8 g/dL (\< 5 mmol/L), Total leukocyte count \< 2,000/µL (2 x 109/L), Platelets \< 50,000/µL (50 x 109/L), Neutrophil count \< 1,000/µL (1 x 109/L)
• •Pregnant or nursing (lactating) women
• •Women of child-bearing potential, defined as all women physiologically capable of becoming pregnant, unless they use a highly effective method of contraception
• •SjS:
• •Sjögren's Syndrome overlap syndromes where another autoimmune disease constitutes the primary illness
• •Required regular use of medications known to cause, as a major side effect, dry mouth / eyes