A Study of RSLV-132 in Subjects With Primary Sjogren's Syndrome

This is a multi-center, double-blind, placebo-controlled study to evaluate the impact of 8 intravenous infusions of RSLV-132 in 28 patients with primary Sjogren's syndrome. Each of the subjects will be randomized 3:1 (active:placebo) and will receive 8 infusions of 10 mg/kg of RSLV-132 or placebo as follows on days:

• 1, 8, 15, 29, 43, 57, 71, and 85

Potential subjects will be screened to assess their eligibility to enter the study within 60 days prior to study entry (i.e., prior to Baseline visit). Following Baseline evaluations on Day 1, subjects will receive their first infusion of RSLV-132 or placebo. Subjects will return to the research unit for follow-up visits as described in Appendix A.

Dose selection rationale: The dose level was chosen based on safety and tolerability data from Protocol 132-02 (multiple ascending dose study in SLE patients). Additionally, in a 6-month toxicology study in cynomolgus monkeys, 50 mg/kg of RSLV-132 was administered by IV infusion weekly. No dose-limiting toxicity was noted, therefore the No Observed Adverse Effect Level is at least 50 mg/kg, providing at least a 5-fold safety margin for this study.

RSLV-132 shall be prepared for each subject from individual stock vials provided by Sponsor. Details of dilution, dose preparation, and administration instructions will be provided in the Study Drug Reference Guide. The dose for each individual shall be based on the subject's body weight.

Inclusion criteria

• Meet 4 of 6 criteria of 2002 American-European Consensus Group (AECG) criteria for Primary Sjogren's Syndrome
• Presence of anti Ro autoantibodies
• Presence of interferon signature

Exclusion criteria

• Use fo hydroxychloroquine within 30 days of baseline
• Use of cyclophosphamide within 180 days of baseline
• Use of oral corticosteroids greater than 10 mg/day
• Known IgG4-related disease