Post-COVID Postural Orthostatic Tachycardia Syndrome Postural Orthostatic Tachycardia SyndromePhase 2POTSNCT05918978
Open Label Extension of Efgartigimod in Adults With Post-COVID-19 POTS
A Phase 2 study testing Efgartigimod in people with Post-COVID Postural Orthostatic Tachycardia Syndrome Postural Orthostatic Tachycardia Syndrome, run by argenx at 9 sites in United States.
Trial summary
The OLE study aims to investigate the safety, efficacy, pharmacodynamics (PD), pharmacokinetics (PK), and immunogenicity of efgartigimod in participants with post-COVID-19 postural orthostatic. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Post-COVID Postural Orthostatic Tachycardia Syndrome Postural Orthostatic Tachycardia Syndrome
- What is being tested?
- Efgartigimod
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 33 participants
- Where
- 9 sitesUnited States
- Study dates
- 20 Jun 2023to 15 Aug 2024
- Phase
- Phase 2
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- The participant has completed the ARGX-113-2104 study without permanent discontinuation of IMP and agrees to directly roll over into the extension study without discontinuation of IMP.
- The participant signs the informed consent form, and can comply with OLE study (ARGX-113-2105) protocol requirements.
- The participant agrees to use contraceptives consistent with local regulations regarding the methods of contraception for those participating in clinical studies. Contraceptive requirements are provided.
- Female participants of childbearing potential must have a negative urine pregnancy test at baseline before receiving IMP.
Who cannot join
- The participant has a clinically significant condition, based on the judgement of the Study Investigator, eg, laboratory abnormalities, 12-lead ECG readings, concomitant medical disease(s), etc., which may place them at undue risk or confound interpretation of study data.
- The participant intends to become pregnant or start breastfeeding during the study.
Trial locations and contacts
9 sites in 1 country.
9 sites in 1 country
United States9 sites
Johns Hopkins University
Baltimore, Maryland, 21205
Brigham and Women's Hospital
Boston, Massachusetts, 02115
University Hospitals, Neurology Clinical Trials
Cleveland, Ohio, 44106
Apex Trials Group
Fort Worth, Texas, 76104
North Shore University HealthSystem
Glenview, Illinois, 60026
UC Sand Diego Sulpizio Cardiovascular Center
La Jolla, California, 92037
Standford Movement Disorder Center
Palo Alto, California, 94304
Pioneer Clinical Research
Rosharon, Texas, 77583
Metrodora Institute
West Valley City, Utah, 84119
About this study
Official title: Open-Label Extension Study to Evaluate the Long-term Safety and Efficacy of Efgartigimod in Adult Patients With Post-COVID-19 Postural Orthostatic Tachycardia Syndrome (PC-POTS) Who Completed Study ARGX-113-2104
The OLE study aims to investigate the safety, efficacy, pharmacodynamics (PD), pharmacokinetics (PK), and immunogenicity of efgartigimod in participants with post-COVID-19 postural orthostatic.
Read the detailed description
Study ARGX-113-2105 is a long-term, single-arm, open-label, multicenter extension of the ARGX-113-2104 study, designed to evaluate the long-term safety of efgartigimod IV in adult patients with PC-POTS. Participants will be enrolled from both active and placebo arms of the ARGX-113-2104 study and will receive efgartigimod IV 10 mg/kg in the extension study without knowledge of their prior treatment arm. To be eligible to enroll in this study, participants must have completed the 24-week treatment period of the ARGX-113-2104 study and must not have permanently discontinued the IMP in that study.
- Conditions
- Post-COVID Postural Orthostatic Tachycardia Syndrome Postural Orthostatic Tachycardia Syndrome
- Being tested
- Efgartigimod
- Keywords
- Tachycardia Post-COVID, Postural Orthostatic Tachycardia Syndrome efgartigimod
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
EfgartigimodDrug
Participants will receive efgartigimod IV 10 mg/kg open label, respectively.
| Study group | Role | What they receive |
|---|---|---|
| Efgartigimod | Experimental | Receive efgartigimod IV 10mg/kg infusions during a treatment period of 48 weeks Receives: Drug: Efgartigimod |
What is being measured
The primary outcome is the main question the study is designed to answer.
Number of Participants With TEAEs, TESAEs and TEAESIs
An adverse event (AE) was any untoward medical occurrence in a clinical study participant, temporally associated with the use of study drug, whether or not considered related to the study drug. A serious adverse event (SAE) was any untoward medical occurrence that at any dose 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 any other medically important event. An adverse event of special interest (AESI) was an AE of scientific and medical concern specific to the sponsor's product or program. Treatment-emergent adverse events (TEAEs) were defined as AEs with onset on or after the first administration of study drug up to and including 60 days after the last study drug administration.
Measured: From the first dose of study drug (Day 1) up to 60 days post last dose of study drug, up to 383 days
Secondary outcomes (9)
Change From Baseline to Weeks 24 and 48 in the COMPASS 31 (2-week Recall Version)
Composite Autonomic Symptom Score (COMPASS) 31 modified version (2-week recall) is a self-rated questionnaire to evaluate the severity and distribution of autonomic symptoms in various autonomic nerve disorders. It consists of 31 questions in 6 weighted domains (orthostatic intolerance, vasomotor, secretomotor, gastrointestinal {GI}-mixed upper and diarrhea, bladder, and pupillomotor). A weighted total score of 0 (mild) to 100 (severe) was determined by adding a maximum raw score for each domain. Higher scores indicated a more severe degree of autonomic symptoms.
Measured: Baseline (Day 1) and Weeks 24 and 48
Change From Baseline to Weeks 24 and 48 in the MaPS
The Malmö POTS Symptom Score (MaPS) score is a dedicated POTS symptom scoring questionnaire. The score consists of 12 questions that assess symptom burden related (tachycardia, palpitations, dizziness, presyncope) and unrelated to orthostatic intolerance (GI symptoms, insomnia, concentration difficulties). Participants graded their symptoms for the past 7 days using a numerical rating scale ranging from 0 (no symptoms) to 10 (very pronounced symptoms). The total score was calculated by summing up the items/individual items and range was 0 to 120 points, with higher scores indicating more severe symptoms.
Measured: Baseline (Day 1) and Weeks 24 and 48
Percentage of Participants With Improved PGI-S at Weeks 24 and 48
The Patient Global Impression-Severity (PGI-S) is a participant-rated, single-item scale to assess the severity of a health condition. The scale was used to assess the severity of symptoms over the past week (1-week recall) and overall experience of symptoms over the past 2 weeks (2-week recall). Both were rated on a 4-point type Likert scale, with scores ranging from 1 (none), 2 (mild), 3 (moderate), and 4 (severe). Higher scores indicate greater symptom severity. An "improved PGI-S" was defined by a change from baseline of -3, -2 and -1.
Measured: Baseline (Day 1) and Weeks 24 and 48
Percentage of Participants With Improved PGI-C at Weeks 24 and 48
The Patient Global Impression-Change (PGIC) is a single-item scale to capture the participant's perception of an overall change in their symptoms from start of study drug. It was rated on a 7-point Likert scale, with scores ranging from 1 (much better), 2 (somewhat better), 3 (a little better), 4 (no change), 5 (a little worse), 6 (somewhat worse), and 7 (much worse). Higher PGI-C scores signify worse outcome. An "improved PGI-C" was defined by a change from baseline of 1, 2 and 3.
Measured: Baseline (Day 1) and Weeks 24 and 48
Change From Baseline to Weeks 24 and 48 in the PROMIS Fatigue Short Form 8a
The Patient-Reported Outcomes Measurement Information System (PROMIS) Fatigue Short Form 8a assesses the impact and perceived fatigue during the last 7 days. This validated 8-question scale has 5 response options, with scores ranging from 1 (not at all) to 5 (very much). Total scores ranged from 8 to 40; higher scores indicated higher fatigue levels and were converted to a T-score with a mean of 50 and standard deviation of 10. A decrease in T-score (negative change from baseline) indicated improvement in fatigue.
Measured: Baseline (Day 1) and Weeks 24 and 48
Change From Baseline to Weeks 24 and 48 in the PROMIS Cognitive Function Short Form 6a
PROMIS Cognitive Function Short Form 6a assesses the frequency of cognitive difficulties experienced in the past 7 days. The questionnaire comprises 6 questions on subjective cognitive difficulties regarding a participant's concentration, memory, language, mental acuity, and perceived changes in cognitive functioning. The participant marks their response on a 5-point Likert scale (1: never and 5: very often). Scores ranged from 6 to 30; higher scores indicated worse perceived cognitive functioning and were converted to a T-score with a mean of 50 and standard deviation of 10. An increase in T-score (positive change from baseline) indicated better cognitive function.
Measured: Baseline (Day 1) and Weeks 24 and 48
Percent Change From Baseline in Total IgG Levels at Weeks 24 and 48
Blood samples for immunoglobulin G (IgG) analysis were collected at specified time points. Total IgG concentrations were quantified using validated methods at a central laboratory.
Measured: Baseline (Day 1) and Weeks 24 and 48
Serum Concentration of Efgartigimod
Serum samples were collected at specified timepoints to determine the concentration of efgartigimod.
Measured: Pre-dose at Baseline (Day 1) and Weeks 1, 4, 12 and 24
Number of Participants With ADAs Against Efgartigimod
Blood samples were collected at specified timepoints to assess anti-drug antibodies (ADAs) against efgartigimod. ADA incidence reported here was defined as total number of participants with treatment-induced and treatment-boosted ADA. Treatment-induced ADA was defined as a baseline negative sample and at least 1 positive post-baseline sample. Treatment-boosted ADA was defined as a baseline positive sample and the titer value increased 4-fold or more compared to baseline.
Measured: From the first dose of study drug (Day 1) up to Week 48
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted26 Jun 2023
- Study start20 Jun 2023
- Primary completion15 Aug 2024
- Study completion15 Aug 2024
Why it stopped: Due to the phase 2 results of the main study (ARGX-113-2104) showing that efgartigimod-treated PC-POTS patients had no clinically meaningful improvement, the decision has been made to terminate this open-label extension study (ARGX-113-2105) study.
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Other trials for Post-COVID Postural Orthostatic Tachycardia Syndrome Postural Orthostatic Tachycardia SyndromeStudies of the same condition, open and under way.
- More trials run by argenxThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 33 participants (actual)
Sponsor and investigators
- Lead sponsor
- argenx
- Sponsor type
- Industry (pharma, biotech, devices)
- Collaborators
- IQVIA Pty Ltd
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05918978
- Sponsor's protocol ID
- ARGX-113-2105
- Acronym
- POTS
- Status last verified
- Oct 2025
- First submitted
- 22 Jun 2023
- Last updated
- 23 Oct 2025
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 23 Oct 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Open-Label Extension Study to Evaluate the Long-term Safety and Efficacy of Efgartigimod in Adult Patients With Post-COVID-19 Postural Orthostatic Tachycardia Syndrome (PC-POTS) Who Completed Study ARGX-113-2104
- ClinicalTrials.gov ID
- NCT05918978
- Acronym / sponsor ID
- POTS / ARGX-113-2105
- Conditions
- Post-COVID Postural Orthostatic Tachycardia Syndrome Postural Orthostatic Tachycardia Syndrome
- Keywords
- Tachycardia Post-COVID, Postural Orthostatic Tachycardia Syndrome efgartigimod
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- TerminatedReason stopped: Due to the phase 2 results of the main study (ARGX-113-2104) showing that efgartigimod-treated PC-POTS patients had no clinically meaningful improvement, the decision has been made to terminate this open-label extension study (ARGX-113-2105) study.
- Enrolment
- 33 participants (actual)
- Lead sponsor
- argenxIndustry (pharma, biotech, devices)
- Collaborators
- IQVIA Pty Ltd
- Study start
- 20 Jun 2023 (actual)
- Primary completion
- 15 Aug 2024 (actual)
- Study completion
- 15 Aug 2024 (actual)
- First posted
- 26 Jun 2023 (actual)
- Results
- Posted 23 Oct 2025
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The OLE study aims to investigate the safety, efficacy, pharmacodynamics (PD), pharmacokinetics (PK), and immunogenicity of efgartigimod in participants with post-COVID-19 postural orthostatic.
Detailed description
Study ARGX-113-2105 is a long-term, single-arm, open-label, multicenter extension of the ARGX-113-2104 study, designed to evaluate the long-term safety of efgartigimod IV in adult patients with PC-POTS. Participants will be enrolled from both active and placebo arms of the ARGX-113-2104 study and will receive efgartigimod IV 10 mg/kg in the extension study without knowledge of their prior treatment arm. To be eligible to enroll in this study, participants must have completed the 24-week treatment period of the ARGX-113-2104 study and must not have permanently discontinued the IMP in that study.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Efgartigimod | Experimental | Drug: EfgartigimodReceive efgartigimod IV 10mg/kg infusions during a treatment period of 48 weeks |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- The participant has completed the ARGX-113-2104 study without permanent discontinuation of IMP and agrees to directly roll over into the extension study without discontinuation of IMP.
- The participant signs the informed consent form, and can comply with OLE study (ARGX-113-2105) protocol requirements.
- The participant agrees to use contraceptives consistent with local regulations regarding the methods of contraception for those participating in clinical studies. Contraceptive requirements are provided.
- Female participants of childbearing potential must have a negative urine pregnancy test at baseline before receiving IMP.
Key exclusion criteria (2 listed)
- The participant has a clinically significant condition, based on the judgement of the Study Investigator, eg, laboratory abnormalities, 12-lead ECG readings, concomitant medical disease(s), etc., which may place them at undue risk or confound interpretation of study data.
- The participant intends to become pregnant or start breastfeeding during the study.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| EfgartigimodParticipants will receive efgartigimod IV 10 mg/kg open label, respectively. | Drug | Efgartigimod |
Primary outcome
Number of Participants With TEAEs, TESAEs and TEAESIs
Time frame: From the first dose of study drug (Day 1) up to 60 days post last dose of study drug, up to 383 days
An adverse event (AE) was any untoward medical occurrence in a clinical study participant, temporally associated with the use of study drug, whether or not considered related to the study drug. A serious adverse event (SAE) was any untoward medical occurrence that at any dose 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 any other medically important event. An adverse event of special interest (AESI) was an AE of scientific and medical concern specific to the sponsor's product or program. Treatment-emergent adverse events (TEAEs) were defined as AEs with onset on or after the first administration of study drug up to and including 60 days after the last study drug administration.
9 secondary outcomes
Change From Baseline to Weeks 24 and 48 in the COMPASS 31 (2-week Recall Version)
Time frame: Baseline (Day 1) and Weeks 24 and 48
Change From Baseline to Weeks 24 and 48 in the MaPS
Time frame: Baseline (Day 1) and Weeks 24 and 48
Percentage of Participants With Improved PGI-S at Weeks 24 and 48
Time frame: Baseline (Day 1) and Weeks 24 and 48
Percentage of Participants With Improved PGI-C at Weeks 24 and 48
Time frame: Baseline (Day 1) and Weeks 24 and 48
Change From Baseline to Weeks 24 and 48 in the PROMIS Fatigue Short Form 8a
Time frame: Baseline (Day 1) and Weeks 24 and 48
Change From Baseline to Weeks 24 and 48 in the PROMIS Cognitive Function Short Form 6a
Time frame: Baseline (Day 1) and Weeks 24 and 48
Percent Change From Baseline in Total IgG Levels at Weeks 24 and 48
Time frame: Baseline (Day 1) and Weeks 24 and 48
Serum Concentration of Efgartigimod
Time frame: Pre-dose at Baseline (Day 1) and Weeks 1, 4, 12 and 24
Number of Participants With ADAs Against Efgartigimod
Time frame: From the first dose of study drug (Day 1) up to Week 48
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 23 Oct 2025.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
9 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing Efgartigimod in people with Post-COVID Postural Orthostatic Tachycardia Syndrome Postural Orthostatic Tachycardia Syndrome, run by argenx at 9 sites in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 2 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: stopped early, as of the sponsor's last update on 23 Oct 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 9 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
Yes. Results are posted in the registry (first posted 23 Oct 2025). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Number of Participants With TEAEs, TESAEs and TEAESIs (time frame: From the first dose of study drug (Day 1) up to 60 days post last dose of study drug, up to 383 days). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 23 Oct 2025.