Loading clinical trials...

Phase 1 Study of ART5803 in Healthy Participants | Clinical Trials | Clareo Health

ACTIVE_NOT_RECRUITINGPHASE1

Phase 1 Study of ART5803 in Healthy Participants

A Phase 1, Randomized, Double-blind, Single Ascending Dose and Multiple Ascending Dose Study to Assess the Safety, Tolerability, and Pharmacokinetics of ART5803 Compared With Placebo in Healthy Participants

NCT06575153•Arialys Therapeutics

View on ClinicalTrials.gov

Summary

The study is a Phase 1, single-center, randomized, double-blind, placebo-controlled, single ascending dose (SAD) and multiple ascending dose (MAD) study to assess the safety, tolerability, pharmacokinetics (PK), and immunogenicity of ART5803 compared with placebo in healthy adult participants

Detailed Description

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is one of the most common causes of autoimmune encephalitis. The disease is caused by the development of autoantibodies against the amino (N)-terminal domain (NTD) of the NMDAR subunit 1 (NR1) that bind and cross link the receptors, leading to receptor internalization and loss of function. Arialys has developed a monovalent (one-armed) antibody, ART5803, that binds to the NTD of the NMDAR NR1 subunit without causing NMDAR inhibition, activation, or receptor internalization, while simultaneously blocking the ability of the pathogenic anti-NMDAR autoantibodies to bind to the receptor. This first-in-human (FIH) study will assess the safety, tolerability, pharmacokinetics (PK), and immunogenicity of ART5803 compared with placebo in healthy participants.

Eligibility

Age

18 - 65 years

Sex

ALL

Healthy Volunteers

Yes

Inclusion Criteria

•1. The participant is a male or female, 18 to 65 years of age, inclusive, at the time of informed consent and has a body mass index (BMI) of ≥18 to ≤32 kg/m²
•2. The participant is healthy, as determined by medical history, physical examinations, and the clinical Investigator's judgment.
•3. The participant must be willing and able to provide written, signed informed consent after the nature of the study has been explained, and prior to any research-related procedures.
•4. The participant must be willing and able to comply with all study procedures.
•5. Sexually active female participants of childbearing potential and male participants with female partner(s) of childbearing potential must be willing to use a highly effective method of contraception while participating in the study.
•6. Female participants of childbearing potential must have a negative pregnancy test at Screening and be willing to have additional pregnancy tests during the study. Females considered not of childbearing potential include those who are surgically sterile (surgical bilateral oophorectomy, bilateral salpingectomy, or hysterectomy) confirmed by medical history or are post-menopausal (i.e., no menstrual bleeding for more than 12 months without an alternative medical cause and confirmation with more than 1 follicle-stimulating hormone measurement of at least \> 40 IU/L \[or higher per local institutional guidelines\]).Women of non-childbearing potential are not required to use any contraceptive method.
•7. Male participants with female partners of childbearing potential must agree to use highly effective methods of contraception, from study drug administration until at least 90 days after the last study drug administration.
•8. Male participants must agree not to donate sperm and female participants must agree not to donate eggs, for the duration of the study and until at least 90 days after the last study drug administration.
•9. Participants must agree to not donate blood for at least 3 months after the end-of-study (EOS) visit

Exclusion Criteria

•1. The participant is pregnant or breastfeeding at Screening or planning to become pregnant (self or partner) at any time during the study.
•2. The participant has used an investigational product or investigational medical device within 30 days prior to Screening, or is required to use any investigational agent prior to completion of all scheduled study assessments.
•3. Has a condition of such severity and acuity, in the opinion of the Investigator, that it warrants immediate surgical intervention or other treatment or may not allow safe participation in the study.
•4. The participant has a history of cancer, apart from squamous cell carcinoma of the skin or basal cell carcinoma of the skin. Squamous cell and basal cell carcinomas should be treated with documented success of curative therapy \>3 months prior to randomization.
•5. The participant has any clinically significant illness, such as cardiovascular, neurologic, pulmonary, hepatic, renal, metabolic, gastrointestinal, urologic, immunologic, endocrine, or psychiatric disease or disorder, or other abnormality, which may interfere with the evaluation or administration of the study drug, interpretation of participant safety or study results, or would make participation in the study an unacceptable risk including any significant acute or chronic medical condition. It is the responsibility of the Investigator to assess the clinical significance; however, consultation with the medical monitor may be warranted.
•6. Has a concurrent disease or condition that, in the view of the Principal Investigator, places the participant at high risk of poor treatment compliance or of not completing the study, or would interfere with study participation or would affect safety. Participants with fully resolved childhood asthma that has had no reoccurrences or hospitalizations remain eligible for participation.
•7. The participant is a regular smoker (cigarettes, e-cigarettes, and vaping included), defined as smoking daily. Participants that are non-daily smokers (up to ≤5 cigarettes per week \[or vaping or e-cigarette equivalent\]) are permitted to participate in the study and must agree to refrain from smoking from 2 weeks before the first study drug administration until the end of the inpatient stay (Part 1: Day 5; Part 2: Day 29).
•8. The participant has a contraindication to undergo LP, including international normalized ratio (INR) \>1.4 or other coagulopathy, platelet cell count of \<120,000/µL, infection at the desired LP site, current use of anti-coagulant medication except for low dose acetylsalicylic acid, degenerative arthritis, spinal scoliosis, back surgery, suspected increased intracranial pressure on history or neurologic exam, non-communicating hydrocephalus or intracranial mass, or prior history of spinal mass or trauma.
•9. The participant has severe drug allergic history or anaphylaxis to 2 or more food products or medicines (including known sensitivity to acetaminophen/paracetamol, diphenhydramine or equivalent antihistamine, methylprednisolone or equivalent glucocorticoid, or lidocaine).
•10. The participant has a known history of allergy or reaction to any component of the investigational agent formulation or placebo, or history of anaphylaxis following any biologic therapy.
+16 more criteria

Locations (1)

Nucleus Network Pty Ltd

Melbourne, Victoria, Australia

Key Dates

Start Date

September 19, 2024

Primary Completion Date

September 11, 2025

Completion Date

March 11, 2026

Last Updated

February 6, 2026

Enrollment

ACTUAL participants

Conditions

Autoimmune Encephalitis

Interventions

ART5803

DRUG

Study of Pathogenic Mechanisms and Identification of Novel Autoantibodies in Autoimmune Encephalitis

NCT07477015

Autoimmune Encephalitis

View study

RECRUITINGNA

Impact of Confirmed Autoimmune Encephalitis on Brain Glucose Metabolism

NCT06079294

Autoimmune Encephalitis

View study

RECRUITING

Medium-term Effects of Treatments in Autoimmune Encephalitis

NCT07133113

Data Source & Attribution

This clinical trial information is sourced from ClinicalTrials.gov, a service of the U.S. National Institutes of Health.

ClinicalTrials.gov last update: February 6, 2026Data synced to Clareo: March 29, 2026

Modifications: This data has been reformatted for display purposes. Eligibility criteria have been parsed into inclusion/exclusion sections. Location data has been geocoded to enable distance-based search. For the authoritative and most current information, please visit ClinicalTrials.gov.

Neither the United States Government nor Clareo Health make any warranties regarding the data. Check ClinicalTrials.gov frequently for updates.

View ClinicalTrials.gov Terms and Conditions

Phase 1 Study of ART5803 in Healthy Participants

Inclusion Criteria

Exclusion Criteria

Study of Pathogenic Mechanisms and Identification of Novel Autoantibodies in Autoimmune Encephalitis

Impact of Confirmed Autoimmune Encephalitis on Brain Glucose Metabolism

Medium-term Effects of Treatments in Autoimmune Encephalitis

Safety and Efficacy of CT103A Cells for Relapsed/Refractory Antibody-associated Inflammatory Diseases of the Nervous System

Metabolic Imaging for Diagnosis and Prognostication of Autoimmune encephalitiS

Neuro-ophthalmology and Autoimmune Encephalitis (NODE)