A Study to Learn About How Well the Medicine Efgartigimod Works to Treat Autoimmune Encephalitis In Children 12 Years or Older and Adults

NCT07583641 · tracked via the Priya Life Science USA tracker

Sponsor

argenx

Phase

Phase 2

Started

2027-04-01

Last updated

2026-09-22

Condition(s) studied

Autoimmune Encephalitis (AE)

Investigational drug(s) / intervention(s)

Efgartigimod PH20 (ARGX-113) SCPlacebo PH20 SC

Efgartigimod PH20 (ARGX-113) SC: subcutaneous administrations of efgartigimod PH20 SC given by prefilled syringe (PFS). For participants aged 12 to \<18 years with body weight ≤50 kg, the study drug will be administered by vial and syringe.

Placebo PH20 SC: subcutaneous administrations of placebo PH20 SC given by prefilled syringe (PFS). For participants aged 12 to \<18 years with body weight ≤50 kg, the study drug will be administered by vial and syringe

Study summary

The POLARIS study is designed to evaluate how well efgartigimod PH20 SC may work (called "efficacy") and how safe it is for people diagnosed with Autoimmune Encephalitis (AIE). The study consists of 4 parts: in part A participants will receive efgartigimod SC; in part B, participants will be randomized to receive either efgartigimod SC or placebo; in part C, participants who completed part B will receive efgartigimod SC; in part D, participants who completed part C will be observed after their last dose of efgartigimod SC. If AIE symptoms return, efgartigimod SC treatment may be restarted during this time.

The maximum overall study duration for participants is up to 3 years. More information can be found in clinicaltrials.argenx.com/polaris

Eligibility

Sex

ALL

Min age

12 Years

Max age

—

Healthy volunteers

Inclusion Criteria: * Is at least 12 years of age. * Meeting at least the criteria for possible AIE according to the Graus criteria. * Part A: Must not have received prior treatment for AIE with PLEX or Ig (participants may have received glucocorticoids); and must not have received PLEX or Ig for any other medical condition in the last 3 months \- Part B: Either completing Part A, or If directly entering Part B, must have received first-line treatment for AIE (i.e. corticosteroids, PLEX, and/or Ig) and have a CASE score of 3 or higher, or a score of 2 or higher in a single sub-item Exclusion Criteria: * Known anti-myelin oligodendrocyte glycoprotein (anti-MOG) antibody positivity. * Any medical condition that would interfere with an accurate assessment of clinical symptoms of AIE. * Recent major surgery (within 3 months of screening) or intention to have major surgery during the study, except for surgeries for AIE-related teratomas and thymomas. * History (within 12 months before screening) of current alcohol, drug (including recreational or prescribed cannabinoids), or medication abuse. * Psychiatric or cognitive impairment unrelated to AIE.

Primary outcome measure(s)

Change in CASE score in the NMDAR population — up to week 24
CASE= Clinical Assessment Scale in Autoimmune Encephalitis; NMDAR=N-methyl-D-aspartate receptor; Neuropsychological Status. The CASE (Clinical Assessment Scale in AIE) includes an assessment of 9 items: seizure, memory dysfunction, psychiatric symptoms, consciousness, language problems, dyskinesia/dystonia, gait instability and ataxia, brainstem dysfunction, weakness. This overall CASE total score ranges from 0 to 27, with a higher score indicating a greater degree of disability.

Trial sites (2)

Facility	City	Region	Status
Center for Neurosciences	Tucson	Arizona
Texas Institute for Neurological Disorders	Sherman	Texas

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Official registry record

This page summarises publicly available registry data for informational purposes — not medical advice. Eligibility is determined by each study team; patients should discuss participation with their clinician.

View NCT07583641 on ClinicalTrials.gov ↗ ← All trials in the USA