A Study to Assess the Safety of ARGX-124 in Healthy Volunteers

A Phase 1, Randomized, Double-Blinded, Placebo-Controlled Study to Investigate the Safety, Tolerability, Pharmacokinetics, Pharmacodynamics, and Immunogenicity of Single and Multiple Ascending Doses of ARGX-124 in Healthy Adult Participants

Status

Recruiting

Phases

Phase 1

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT07377396

Enrollment

104

Registered

2026-01-29

Start date

2026-01-26

Completion date

2026-12-31

Last updated

2026-03-06

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Healthy Volunteers

Brief summary

This study aims to assess the safety of ARGX-124 in healthy adults. Another aim is to measure the amount of ARGX-124 in the blood over time to learn how it acts and moves in the body and how the immune system responds to it. Participants will remain in the study for up to approximately 23 weeks.

Interventions

BIOLOGICALARGX-124

Administrations of ARGX-124

OTHERPlacebo

Administrations of placebo comparator

Study design

Allocation

RANDOMIZED

Intervention model

PARALLEL

Primary purpose

TREATMENT

Masking

QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)

Eligibility

Sex/Gender

ALL

Age

18 Years to 65 Years

Healthy volunteers

Yes

Inclusion criteria

* Is at least the local legal age of consent and aged 18 to 65 years, inclusive, when signing the ICF. * Is a female of Nonchildbearing Potential (postmenopausal or surgically sterilized) or a male. * Has a body weight between 50 and 120 kg and a BMI between 18 and 30.5 kg/m2, inclusive.

Exclusion criteria

* Has any current or past clinically meaningful medical or psychiatric condition that, in the investigator's opinion, would confound the study results or put the participant at undue risk. * Has IgG levels \<6.0 g/L at screening. * Has a history of an immunosuppressive disease or an immunosuppressive condition at screening. * Previously participated in an ARGX-124, ARGX-213, or efgartigimod clinical study and received at least 1 dose of the study drug.

Design outcomes

Primary

Measure	Time frame	Description
Incidence of AEs, SAEs and AEs leading to ARGX-124 discontinuation	Up to 23 weeks	AE : adverse event ; SAE : serious adverse event.

Secondary

Measure	Time frame	Description
Maximum observed serum concentration (Cmax)	Up to 23 weeks	—
Percent change from baseline in total IgG levels in serum over time	Up to 23 weeks	IgG : immunoglobulin G
Incidence of ADA against ARGX-124 in serum	Up to 23 weeks	ADA : anti-drug antibodies

Countries

Canada

Contacts

CONTACTSabine Coppieters, MD

clinicaltrials@argenx.com857-350-4834

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Mar 7, 2026