A Study of the Safety and Effectiveness of Efgartigimod in Patients With Primary Sjögren's Syndrome (pSS) (rho)

A Phase 2, Randomized, Placebo-controlled, Parallel-group, Double-blinded, proof-of Concept Study to Evaluate the Safety and Efficacy of Intravenous Efgartigimod in Adult Participants With Primary Sjögren's Syndrome

The purpose of this study is to assess the efficacy and safety of human FcRn blocking therapy with efgartigimod compared to placebo, in participants with pSS.

Study Overview

• Status: Completed
• Conditions: Primary Sjögren's Syndrome
• Intervention / Treatment: Biological: Efgartigimod; Biological: Placebo

Detailed Description

Primary Sjogren Syndrome (pSS) is an autoimmune disease with still unmet treatment needs. Efgartigimod, a human FcRn antagonist, has the potential to successfully treat pSS and improve disease manifestations by the reduction of IgG autoantibodies and immune complexes in pSS. The study design is randomized, double-blinded, and placebo-controlled to evaluate the effect of efgartigimod administered as an IV infusion compared to placebo. The study consists of a treatment period when all participants will receive infusions of IP/placebo for 24 weeks. At the end of the randomized treatment period, eligible participants may roll over to an OLE study or remain in this study through the end of the 56-day follow-up period.

• Study Type: Interventional
• Enrollment (Actual): 34
• Phase: Phase 2

Contacts and Locations

Study Locations

• Belgium
  • Gent, Belgium, 9000
    • Universitair Ziekenhuis Gent
• Hungary
  • Debrecen, Hungary, 4032
    • Debreceni Egyetem
  • Szekesfehervar, Hungary, 8000
    • Vita Verum Medical Egeszsegugyi Szolgaltato Bt.
• Netherlands
  • Groningen, Netherlands, 9713 GZ
    • Universitair Medisch Centrum Groningen , Dept of Rheumatology and Clinical Immunology
• Poland
  • Elblag, Poland, 82-300
    • Ambulatorium Barbara Bazela
  • Grodzisk Mazowiecki, Poland, 05-825
    • MCBK Iwona Czajkowska Anna Podrażka- Szczepaniak S.C.
  • Krakow, Poland, 31-501
    • Futuremeds Krakow
  • Kraków, Poland, 30-363
    • Centrum Medyczne Plejady
  • Lublin, Poland, 20-412
    • ETG Lublin
  • Lublin, Poland, 20-607
    • Reumed Spolka z o.o.
  • Poznan, Poland, 60-848
    • Clinical Research Center Spółka z ograniczoną odpowiedzialnością Medic-R Sp.k.
  • Skórzewo, Poland, 60-185
    • Centrum Medyczne Pratia Poznan
  • Warsaw, Poland, 03-291
    • Futuremeds Targowek
  • Warsaw, Poland, 02-691
    • Centrum Medyczne Reuma Park
  • Warszawa, Poland, 00-874
    • MICS Centrum Medyczne Warszawa
  • Warszawa, Poland, 02-637
    • KO-Med - Centrum Badań Medycznych NIGRiR
  • Wroclaw, Poland, 50-088
    • FutureMeds Wroclaw

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Is at least the legal age of consent for clinical trials when signing the informed consent form
• Is capable of providing signed informed consent and complying with protocol requirements
• Agrees to use contraceptive measures consistent with local regulations and measures described in the protocol
• Meets the following criteria at screening: ACR/EULAR 2016 pSS who met criteria ≤7 years before screening; ESSDAI ≥5; Anti-Ro/SS-A positive; Residual salivary flow (UWSF rate >0 and/or SWSF rate >0.10)

Exclusion Criteria:

• Known autoimmune disease or any medical condition that, in the investigator's judgment,would interfere with an accurate assessment of clinical symptoms of pSS or puts the participant at undue risk
• History of malignancy unless considered cured by adequate treatment with no evidence of recurrence for ≥3 years before the first administration of IMP.
• Adequately treated participants with the following cancers may be included at any time: Basal cell or squamous cell skin cancer; Carcinoma in situ of the cervix; Carcinoma in situ of the breast; Incidental histological finding of prostate cancer (TNM stage T1a or T1b) Clinically significant uncontrolled active acute or chronic bacterial, viral, or fungal infection
• Positive serum test at screening for an active infection with any of the following: HBV that is indicative of an acute or chronic infection, unless associated with a negative HBsAg or negative HBV DNA test; HCV based on HCV antibody assay unless a negative RNA test is available; HIV based on test results of a CD4 count of <200 cells/mm3 that are associated with an AIDS-defining condition, HIV based on test results of a CD4 count of >200 cells/mm3 not adequately treated with antiviral therapy
• Clinically significant disease, recent major surgery (within 3 months of screening), or intention to have surgery during the study; or any other medical condition that, in the investigator's opinion, would confound the results of the study or put the participant at undue risk
• Immunoglobulin G (IgG) levels cannot be below a certain threshold ( 4g/L)
• Positive covid test at study start
• Some of the medications such as vaccines with live components or medicines that may be prescribed cannot be taken either shortly before or during this study
• Current participation in another interventional clinical study or previously participation in an efgartigimod clinical study and treatment with ≥1 dose of IMP
• Known hypersensitivity to IMP or 1 of its excipients
• History (within 12 months of screening) of current alcohol, drug, or medication abuse as assessed by the investigator
• Pregnant or lactating state or intention to become pregnant during the study
• Secondary Sjögren's syndrome overlap syndromes where another confirmed autoimmune rheumatic or systemic inflammatory condition is the primary diagnosis
• Chinese traditional medicine with known immunomodulatory action

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Efgartigimod IV arm; patients receiving infusions of Efgartigimod IV	Biological: Efgartigimod; Patients receiving efgartigimod infusions
Placebo Comparator: Placebo arm; patients receiving infusions of placebo IV	Biological: Placebo; Patients receiving placebo infusions

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Percentage of Participants Meeting Overall CRESS Response of at Least 3 of 5 Items at Week 24	A Composite of Relevant Endpoints for Sjögren's Syndrome (CRESS) responder is defined as improvements in at least 3 of the 5 items of CRESS (systemic disease activity, patient-reported symptoms, tear gland function, salivary gland function and serology. The score ranges from 0 to 9 (higher score = worse symptoms).	Week 24

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of Participants With TEAEs, AESI, and SAEs	A treatment-emergent adverse event (TEAE): adverse events reported from the first dose up to and including 60 days after the final dose were considered treatment-emergent. Serious adverse event (SAE): adverse event that resulted in death, was life threatening, required inpatient hospitalization or prolongation of existing hospitalization, resulted in persistent or significant disability/incapacity, was a congenital anomaly/birth defect or other situations. Adverse event of special interest (AESI): adverse event related to 'Infections and infestations'.	Up to 32 weeks
Percentage of Participants With MCII in ESSDAI at Week 24	European Alliance of Associations for Rheumatology (EULAR) Sjögren's Syndrome Disease Activity Index (ESSDAI) measures systemic disease activity in participants with pSjD and consists of 11 organ-specific domains and 1 biological domain that contribute to disease activity level scoring. Each domain is given a certain weight, which gives a score between 0 and 123 (higher score =worse symptoms). Minimally clinically important improvement (MCII) in ESSDAI was defined as improvement of at least 3 points in ESSDAI score at Week 24.	Week 24
Percentage of Participants With Low Disease Activity in ESSDAI at Week 24	ESSDAI measures systemic disease activity in participants with pSjD and consists of 11 organ-specific domains and 1 biological domain that contribute to disease activity level scoring. Each domain is given a certain weight, which gives a score between 0 and 123 (higher score =worse symptoms). Low disease activity in ESSDAI was defined as ESSDAI score of less than 5 at Week 24.	Week 24
Percentage of Participants With MCII in clinESSDAI at Week 24	Clinical (clin)ESSDAI includes the same 11 organ-specific domains as ESSDAI but with different domain weighting and without the biological domain. This way any change in clinESSDAI score would reflect disease specific features, irrespective of B-cell activity. The clinESSDAI score ranges between 0-135 (higher score = worse symptoms). Minimal clinically important improvement (MCII) in clinESSDAI was defined as improvement of at least 3 points in clinESSDAI score at Week 24.	Week 24
Percentage of Participants With Low Disease Activity in clinESSDAI at Week 24	clinESSDAI includes the same 11 organ-specific domains as ESSDAI but with different domain weighting and without the biological domain. This way any change in clinESSDAI score would reflect disease specific features, irrespective of B-cell activity. The clinESSDAI score ranges between 0-135 (higher score = worse symptoms). Low disease activity in clinESSDAI was defined as clinESSDAI score of less than 5 at Week 24.	Week 24
Percentage of Participants With MCII in ESSPRI at Week 24	Minimal clinically important improvement in ESSPRI was defined as decrease of 1 point or at least ≥15% at Week 24. ESSPRI is a questionnaire that has been developed to measure self-reported symptoms in participants with pSjD. The score ranges from 0 (no symptoms) to 10 (more symptoms).	Week 24
Change From Baseline in ESSDAI Score at Week 24	ESSDAI measures systemic disease activity in participants with pSjD and consists of 11 organ-specific domains and 1 biological domain that contribute to disease activity level scoring. Each domain is given a certain weight, which gives a score between 0 and 123 (higher score = worse symptoms).	Baseline (Day 1) and Week 24
Change From Baseline in clinESSDAI Score at Week 24	clinESSDAI includes the same 11 organ-specific domains as ESSDAI but with different domain weighting and without the biological domain. This way any change in clinESSDAI score would reflect disease specific features, irrespective of B-cell activity. The clinESSDAI score ranges between 0-135 (higher score = worse symptoms).	Baseline (Day 1) and Week 24
Change From Baseline in ESSPRI Score at Week 24	ESSPRI is a questionnaire that has been developed to measure self-reported symptoms in participants with pSjD. The score ranges from 0 (no symptoms) to 10 (more symptoms).	Baseline (Day 1) and Week 24
Percentage of Participants With STAR Score of at Least 5 at Week 24	Sjögren's Tool for Assessing Response (STAR) is a composite endpoint assessing multiple clinically relevant disease features. A STAR responder is defined as a score of at least 5 points. Due to the weighting, participants must be a responder on either systemic disease activity (ESSDAI), patient-reported symptoms (ESSPRI), or both to be an overall STAR responder. The score ranges between 0 and 9 (higher score = worse outcome).	Week 24
Plasma Concentration of Efgartigimod	Serum samples were collected at indicated time points to assess the pharmacokinetic (PK) profile of efgartigimod.	Pre-dose at Day 1, Weeks 1, 2, 4, 8, 12, 16, and 20; 30 minutes post-dose at Day 1, Weeks 1, 2, 4, 8, 12, 16, 20 and 24
Percentage Change From Baseline in Total IgG Levels in Serum at Week 24	Blood samples were collected at indicated timepoints to assess the total Immunoglobulin (Ig)G levels in serum.	Baseline (Day 1) and Week 24
Number of Participants With ADA Against Efgartigimod in Serum	Blood samples were collected to assess anti-drug antibodies (ADAs) against efgartigimod. Treatment-boosted ADA was defined as participants who had a baseline positive sample and the titer value increased 4-fold or more compared to baseline. Treatment-induced ADA was defined as participants who had a baseline negative sample and at least 1 positive post-baseline samples. Treatment-unaffected ADA was defined as participants who had a baseline positive sample, but the titer value did not increase 4-fold or more compared to baseline.	Up to Week 24

Collaborators and Investigators

• Sponsor: argenx
• Collaborators: IQVIA Pty Ltd

Study record dates

Study Major Dates

• Study Start (Actual): April 4, 2023
• Primary Completion (Actual): January 29, 2024
• Study Completion (Actual): February 12, 2024

Study Registration Dates

• First Submitted: February 1, 2023
• First Submitted That Met QC Criteria: April 5, 2023
• First Posted (Actual): April 18, 2023

Study Record Updates

• Last Update Posted (Actual): July 18, 2025
• Last Update Submitted That Met QC Criteria: June 30, 2025
• Last Verified: June 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Musculoskeletal Diseases; Mouth Diseases; Stomatognathic Diseases; Pathologic Processes; Arthritis; Joint Diseases; Rheumatic Diseases; Connective Tissue Diseases; Autoimmune Diseases; Immune System Diseases; Disease; Eye Diseases; Arthritis, Rheumatoid; Xerostomia; Salivary Gland Diseases; Dry Eye Syndromes; Lacrimal Apparatus Diseases; Syndrome; Sjogren's Syndrome
• Other Study ID Numbers: ARGX-113-2106; 2021-005911-30 (EudraCT Number)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No