Autoimmune Encephalitis Caused by N-Methyl D-Aspartate Receptor AntibodyPhase 1NCT06753955
Phase 1 Study of ART5803 Safety and PK After IVIG in Healthy Participants
A Phase 1 study testing ART5803 and Intravenous immunoglobulin (IVIG) in people with Autoimmune Encephalitis Caused by N-Methyl D-Aspartate Receptor Antibody and Autoimmune Encephalitis Caused by N-Methyl D-Aspartate Receptor Antibody (Disorder), run by Arialys Therapeutics at 1 site in Australia.
Trial summary
This study will evaluate the safety, tolerability, and pharmacokinetics (PK) of ART5803 following IVIG administration in healthy participants to investigate the potential interactions between ART5803 and IVIG Read more about this study
- Who is it for?
- Ages 18 to 65 yearsHealthy volunteers can take part
- Conditions the study is for
- Autoimmune Encephalitis Caused by N-Methyl D-Aspartate Receptor Antibody, Autoimmune Encephalitis Caused by N-Methyl D-Aspartate Receptor Antibody (Disorder), Autoimmune Encephalitis
- What is being tested?
- ART5803 and Intravenous immunoglobulin (IVIG)
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 7 participants
- Where
- 1 siteAustralia
- Study dates
- 25 Feb 2025to 19 Aug 2025
- Phase
- Phase 1
- Are there results?
- None posted in the registry
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 to 65 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- 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.
- 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) between 18 and 32 kg/m2 (inclusive) and a weight not exceeding 100 kg.
- The participant is healthy, as determined by medical history, physical examinations, and the clinical Investigator's judgment.
- The participant must be willing and able to comply with all study procedures.
- 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. The contraceptive methods used for male and female participants must be documented in the source documents.
- 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.
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- 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.
- 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.
- Participants must agree not to donate blood for at least 3 months after the end-of-study (EOS) visit.
Who cannot join
- The participant is pregnant or breastfeeding at Screening or planning to become pregnant (self or partner) at any time during the study.
- The participant has used an investigational product or medical device within 30 days of Screening or for 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. The Investigator is responsible for assessing the clinical significance of findings from health assessments and evaluations; however, consultation with the medical monitor may be warranted.
- 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 with no reoccurrences or hospitalizations remain eligible for participation.
- The participant is a regular smoker (cigarettes, e-cigarettes, and vaping included), defined as smoking daily. Participants who 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 during the in-patient stays.
- 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 examination, non-communicating hydrocephalus or intracranial mass, or prior history of spinal mass or trauma.
- The participant has a 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).
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- The participant has a known history of allergy or reaction to any component of the investigational agent formulation or IVIG or any of its components, or a history of anaphylaxis or severe systemic reaction to blood products or following any biologic therapy.
- The participant has a history of alcohol abuse or drug addiction in the past 12 months.
- The participant has undergone significant trauma or major surgery within 4 weeks of Screening.
- The participant has had a vaccination with live virus, attenuated live virus, or any live viral components within 2 weeks prior to study drug administration or is planning to receive these vaccines at any time during the study and up to 8 weeks following the last study drug administration.
- The participant has ANY of the following abnormalities in clinical laboratory tests at Screening, as assessed by the study-specific laboratory and confirmed by a single repeat if deemed necessary:
- Serum creatinine level more than 1.25×upper limit of normal (ULN) or an estimated glomerular filtration rate value <80 mL/min/1.73 m2 calculated with the Chronic Kidney Disease Epidemiology Collaboration formula and more than trace protein in urine.
- Total bilirubin, aspartate aminotransferase (AST) or alanine aminotransferase (ALT) values more than >2×ULN. Note: participants with a history of Gilbert's syndrome are excluded from participation in the study.
- Hematological or coagulation values outside the normal reference range for local laboratory results unless regarded as not clinically significant.
- Confirmed positive test for hepatitis B serology (hepatitis B surface antigen and core antibody) and/or hepatitis C polymerase chain reaction.
- Values indicating a deficiency of immunoglobulin A (IgA) or anti-IgA antibodies.
- The participant has a 12-lead ECG demonstrating an abnormal corrected QT interval by Fridericia (QTcF) (>450 ms for males, >470 ms for females) or a QRS interval >120 ms. If QTcF is abnormal (>450 ms for males, >470 ms for females) or a QRS interval >120 ms, the ECG should be repeated 2 more times, and the average of the 3 QTcF or QRS interval values (i.e., the initial reading plus 2 repeats for a total of 3 readings, averaged) should be used to determine the participant's eligibility.
- The participant has Investigator determined coronavirus disease of 2019 (COVID 19) within 4 weeks prior to Day 1, received the COVID-19 vaccine within 2 weeks prior to study drug administration, or plans to receive a COVID-19 vaccine within 9 weeks after study drug administration. Regional and site COVID-19 testing policies should be followed throughout the study.
- The participant has a positive urine or blood result for drugs of abuse (defined as any illicit drug use) at Screening or Check-in (Day -1).
- The participant has received any NMDAR modulator other than the study drug (e.g., ketamine, memantine, dextromethorphan, amantadine, ifenprodil, phencyclidine [PCP], acamprosate, D-cycloserine) or IVIG from within 30 days or 5 half lives of the other NMDAR modulator or IVIG (whichever is longer) of study drug administration until the end of the study.
- The participant has a known history of primary immunodeficiency (congenital or acquired) or an underlying condition such as human immunodeficiency virus infection.
- The participant has had a bacillus of Calmette and Guérin vaccine within 1 year of enrollment.
- The participant has a history of severe depression, bipolar disease, or schizophrenia.
- The participant has a risk of suicide per the C-SSRS (a score of 4 or 5 on ideation or any suicidal behavior) or, according to the Investigator's clinical judgment, has made a suicide attempt in the previous 6 months, or has a history of deliberate self-harm in the past 6 months.
Trial locations and contacts
1 site in 1 country.
About this study
Official title: A Phase 1, Open-label Study to Evaluate the Safety, Tolerability, and Pharmacokinetics of a Single-dose of ART5803 Following IVIG Administration in Healthy Participants
This study will evaluate the safety, tolerability, and pharmacokinetics (PK) of ART5803 following IVIG administration in healthy participants to investigate the potential interactions between ART5803 and IVIG
Read the 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.
In treating anti-NMDAR encephalitis, intravenous immunoglobulin (IVIG) is commonly administered in conjunction with corticosteroids. Consequently, it is anticipated that IVIG may be administered to the target population prior to ART5803. IVIG has a long half-life and competitive binding of IVIG to the neonatal fragment crystallization receptor (FcRn) may result in FcRn saturation. This can potentially lead to increased clearance and/or impaired tissue distribution of ART5803 and decrease the cerebrospinal fluid (CSF) exposure to ART5803 through competition on FcRn at the blood-brain barrier (BBB).
- Conditions
- Autoimmune Encephalitis Caused by N-Methyl D-Aspartate Receptor Antibody, Autoimmune Encephalitis Caused by N-Methyl D-Aspartate Receptor Antibody (Disorder), Autoimmune Encephalitis
- Being tested
- ART5803, Intravenous immunoglobulin (IVIG)
- Keywords
- Anti-N-methyl-D-aspartate receptor (NMDAR), Encephalitis, Anti-N-methyl-D-aspartate receptor (NMDAR) Encephalitis, Intravenous immunoglobulin (IVIG)
- Medical subject headings
- Autoimmune Diseases of the Nervous System, Encephalitis
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
ART5803Drug
A monovalent (one-armed) antibody, 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.
Intravenous immunoglobulin (IVIG)Drug
Administered as background treatment prior to the investigational product
| Study group | Role | What they receive |
|---|---|---|
| Cohort 1 | Other | IVIG IV infusion (not experimental) followed by ART5803 IV infusion (experimental) Receives: Drug: ART5803; Drug: Intravenous immunoglobulin (IVIG) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Safety will be assessed by the incidence and severity of treatment-emergent adverse events (TEAEs)
ART5803 safety, as measured by the number of treatment emergent adverse events
Measured: 13 Weeks
Safety will be assessed by clinically significant changes in physical and neurological examination findings
ART5803 safety, will be assessed by clinically significant changes in physical and neurological examination findings
Measured: 13 Weeks
Safety by assessed by clinically significant changes in vital signs
ART5803 safety, will be assessed by clinically significant changes in vital signs including systolic and diastolic blood pressure, pulse rate, respiration rate, and body temperature
Measured: 13 Weeks
Safety by assessed by clinically significant changes in clinical laboratory outcomes
ART5803 safety, will be assessed by clinically significant changes in clinical laboratory outcomes including clinical chemistry, hematology, coagulation, and urinalysis
Measured: 13 Weeks
Safety by assessed by clinically significant changes in 12-lead ECG findings
ART5803 safety, will be assessed by clinically significant changes 12-lead ECG findings
Measured: 13 Weeks
Safety by assessed by clinically significant changes in concomitant medications
ART5803 safety, will be assessed by clinically significant changes in concomitant medications
Measured: 13 Weeks
Safety by assessed by clinically significant changes in presence of anti-drug antibodies (ADAs)
ART5803 safety, will be assessed by clinically significant changes in presence of anti-drug antibodies (ADAs)
Measured: 13 Weeks
Safety will be assessed by incidence of dose-limiting toxicity (DLTs)
ART5803 safety, will be assessed by incidence of dose-limiting toxicity (DLTs)
Measured: 13 Weeks
Safety will be assessed by change in suicidal tendency measured by Columbia-Suicide Severity Rating Scale (C-SSRS)
ART5803 safety, will be assessed by change in suicidal tendency as measured by the incidence of positive responses (Yes) to Item 4 or 5 on the Columbia-Suicide Severity Rating Scale (C-SSRS)
Measured: 13 Weeks
To assess the pharmacokinetics (PK) of single IV dose of ART5803 following prior doses of IVIG
To characterize and compare the PK profile of single IV dose of ART5803 following prior doses of IVIG as measured by maximum concentration (Cmax)
Measured: 13 Weeks
To assess the pharmacokinetics (PK) of single IV dose of ART5803 following prior doses of IVIG
To characterize and compare the PK profile of single IV dose of ART5803 following prior doses of IVIG as measured by last time point with measurable concentration (Clast)
Measured: 13 Weeks
To assess the pharmacokinetics (PK) of single IV dose of ART5803 following prior doses of IVIG
To characterize and compare the PK profile of single IV dose of ART5803 following prior doses of IVIG as measured by minimum concentration (Cmin)
Measured: 13 Weeks
To assess the pharmacokinetics (PK) of single IV dose of ART5803 following prior doses of IVIG
To characterize and compare the PK profile of single IV dose of ART5803 following prior doses of IVIG as measured by time at which Cmax is observed (tmax)
Measured: 13 Weeks
To assess the pharmacokinetics (PK) of single IV dose of ART5803 following prior doses of IVIG
To characterize and compare the PK profile of single IV dose of ART5803 following prior doses of IVIG as measured by time at which Clast is observed (tlast)
Measured: 13 Weeks
To assess the pharmacokinetics (PK) of single IV dose of ART5803 following prior doses of IVIG
To characterize and compare the PK profile of single IV dose of ART5803 following prior doses of IVIG as measured by area under the curve from time 0 to the last measurable concentration (AUC0-t)
Measured: 13 Weeks
To assess the pharmacokinetics (PK) of single IV dose of ART5803 following prior doses of IVIG
To characterize and compare the PK profile of single IV dose of ART5803 following prior doses of IVIG as measured by area under the curve from time 0 extrapolated to infinity (AUC0-∞)
Measured: 13 Weeks
To assess the pharmacokinetics (PK) of single IV dose of ART5803 following prior doses of IVIG
To characterize and compare the PK profile of single IV dose of ART5803 following prior doses of IVIG as measured by the half-life (t½)
Measured: 13 Weeks
To assess the pharmacokinetics (PK) of single IV dose of ART5803 following prior doses of IVIG
To characterize and compare the PK profile of single IV dose of ART5803 following prior doses of IVIG as measured by the volume of distribution (Vd)
Measured: 13 Weeks
To assess the pharmacokinetics (PK) of single IV dose of ART5803 following prior doses of IVIG
To characterize and compare the PK profile of single IV dose of ART5803 following prior doses of IVIG as measured by by clearance (CL)
Measured: 13 Weeks
To assess the pharmacokinetics (PK) of single IV dose of ART5803 following prior doses of IVIG
To asses the CSF/serum ratio of ART5803 at multiple time points
Measured: 13 Weeks
Secondary outcomes (1)
To assess the immunogenicity of a single IV dose of ART5803 following prior doses of IVIG
To assess the incidence of anti-drug antibodies (ADAs) in serum from a single IV dose of ART5803 following prior doses of IVIG
Measured: 13 Weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted31 Dec 2024
- Study start25 Feb 2025
- Primary completion2 Jul 2025
- Study completion19 Aug 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Autoimmune Encephalitis Caused by N-Methyl D-Aspartate Receptor AntibodyStudies of the same condition, open and under way.
- 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 1
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 7 participants (actual)
Sponsor and investigators
- Lead sponsor
- Arialys Therapeutics
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Sankalp Gokhale, MD, MBA, Study chair, Arialys Therapeutics
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06753955
- Sponsor's protocol ID
- ART5803-102
- Status last verified
- Apr 2026
- First submitted
- 23 Dec 2024
- Last updated
- 27 Apr 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 27 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Phase 1, Open-label Study to Evaluate the Safety, Tolerability, and Pharmacokinetics of a Single-dose of ART5803 Following IVIG Administration in Healthy Participants
- ClinicalTrials.gov ID
- NCT06753955
- Acronym / sponsor ID
- ART5803-102
- Conditions
- Autoimmune Encephalitis Caused by N-Methyl D-Aspartate Receptor Antibody, Autoimmune Encephalitis Caused by N-Methyl D-Aspartate Receptor Antibody (Disorder), Autoimmune Encephalitis
- Keywords
- Anti-N-methyl-D-aspartate receptor (NMDAR), Encephalitis, Anti-N-methyl-D-aspartate receptor (NMDAR) Encephalitis, Intravenous immunoglobulin (IVIG)
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 7 participants (actual)
- Lead sponsor
- Arialys TherapeuticsIndustry (pharma, biotech, devices)
- Study start
- 25 Feb 2025 (actual)
- Primary completion
- 2 Jul 2025 (actual)
- Study completion
- 19 Aug 2025 (actual)
- First posted
- 31 Dec 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study will evaluate the safety, tolerability, and pharmacokinetics (PK) of ART5803 following IVIG administration in healthy participants to investigate the potential interactions between ART5803 and IVIG
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.
In treating anti-NMDAR encephalitis, intravenous immunoglobulin (IVIG) is commonly administered in conjunction with corticosteroids. Consequently, it is anticipated that IVIG may be administered to the target population prior to ART5803. IVIG has a long half-life and competitive binding of IVIG to the neonatal fragment crystallization receptor (FcRn) may result in FcRn saturation. This can potentially lead to increased clearance and/or impaired tissue distribution of ART5803 and decrease the cerebrospinal fluid (CSF) exposure to ART5803 through competition on FcRn at the blood-brain barrier (BBB).
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Cohort 1 | Other | Drug: ART5803, Drug: Intravenous immunoglobulin (IVIG)IVIG IV infusion (not experimental) followed by ART5803 IV infusion (experimental) |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (9 listed)
- 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.
- 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) between 18 and 32 kg/m2 (inclusive) and a weight not exceeding 100 kg.
- The participant is healthy, as determined by medical history, physical examinations, and the clinical Investigator's judgment.
- The participant must be willing and able to comply with all study procedures.
- 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. The contraceptive methods used for male and female participants must be documented in the source documents.
Key exclusion criteria (24 listed)
- The participant is pregnant or breastfeeding at Screening or planning to become pregnant (self or partner) at any time during the study.
- The participant has used an investigational product or medical device within 30 days of Screening or for 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. The Investigator is responsible for assessing the clinical significance of findings from health assessments and evaluations; however, consultation with the medical monitor may be warranted.
- 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 with no reoccurrences or hospitalizations remain eligible for participation.
- The participant is a regular smoker (cigarettes, e-cigarettes, and vaping included), defined as smoking daily. Participants who 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 during the in-patient stays.
- 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 examination, non-communicating hydrocephalus or intracranial mass, or prior history of spinal mass or trauma.
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 |
|---|---|---|
| ART5803A monovalent (one-armed) antibody, 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. | Drug | Cohort 1 |
| Intravenous immunoglobulin (IVIG)Administered as background treatment prior to the investigational product | Drug | Cohort 1 |
Primary outcome
Safety will be assessed by the incidence and severity of treatment-emergent adverse events (TEAEs)
Time frame: 13 Weeks
ART5803 safety, as measured by the number of treatment emergent adverse events
Safety will be assessed by clinically significant changes in physical and neurological examination findings
Time frame: 13 Weeks
ART5803 safety, will be assessed by clinically significant changes in physical and neurological examination findings
Safety by assessed by clinically significant changes in vital signs
Time frame: 13 Weeks
ART5803 safety, will be assessed by clinically significant changes in vital signs including systolic and diastolic blood pressure, pulse rate, respiration rate, and body temperature
Safety by assessed by clinically significant changes in clinical laboratory outcomes
Time frame: 13 Weeks
ART5803 safety, will be assessed by clinically significant changes in clinical laboratory outcomes including clinical chemistry, hematology, coagulation, and urinalysis
Safety by assessed by clinically significant changes in 12-lead ECG findings
Time frame: 13 Weeks
ART5803 safety, will be assessed by clinically significant changes 12-lead ECG findings
Safety by assessed by clinically significant changes in concomitant medications
Time frame: 13 Weeks
ART5803 safety, will be assessed by clinically significant changes in concomitant medications
Safety by assessed by clinically significant changes in presence of anti-drug antibodies (ADAs)
Time frame: 13 Weeks
ART5803 safety, will be assessed by clinically significant changes in presence of anti-drug antibodies (ADAs)
Safety will be assessed by incidence of dose-limiting toxicity (DLTs)
Time frame: 13 Weeks
ART5803 safety, will be assessed by incidence of dose-limiting toxicity (DLTs)
Safety will be assessed by change in suicidal tendency measured by Columbia-Suicide Severity Rating Scale (C-SSRS)
Time frame: 13 Weeks
ART5803 safety, will be assessed by change in suicidal tendency as measured by the incidence of positive responses (Yes) to Item 4 or 5 on the Columbia-Suicide Severity Rating Scale (C-SSRS)
To assess the pharmacokinetics (PK) of single IV dose of ART5803 following prior doses of IVIG
Time frame: 13 Weeks
To characterize and compare the PK profile of single IV dose of ART5803 following prior doses of IVIG as measured by maximum concentration (Cmax)
To assess the pharmacokinetics (PK) of single IV dose of ART5803 following prior doses of IVIG
Time frame: 13 Weeks
To characterize and compare the PK profile of single IV dose of ART5803 following prior doses of IVIG as measured by last time point with measurable concentration (Clast)
To assess the pharmacokinetics (PK) of single IV dose of ART5803 following prior doses of IVIG
Time frame: 13 Weeks
To characterize and compare the PK profile of single IV dose of ART5803 following prior doses of IVIG as measured by minimum concentration (Cmin)
To assess the pharmacokinetics (PK) of single IV dose of ART5803 following prior doses of IVIG
Time frame: 13 Weeks
To characterize and compare the PK profile of single IV dose of ART5803 following prior doses of IVIG as measured by time at which Cmax is observed (tmax)
To assess the pharmacokinetics (PK) of single IV dose of ART5803 following prior doses of IVIG
Time frame: 13 Weeks
To characterize and compare the PK profile of single IV dose of ART5803 following prior doses of IVIG as measured by time at which Clast is observed (tlast)
To assess the pharmacokinetics (PK) of single IV dose of ART5803 following prior doses of IVIG
Time frame: 13 Weeks
To characterize and compare the PK profile of single IV dose of ART5803 following prior doses of IVIG as measured by area under the curve from time 0 to the last measurable concentration (AUC0-t)
To assess the pharmacokinetics (PK) of single IV dose of ART5803 following prior doses of IVIG
Time frame: 13 Weeks
To characterize and compare the PK profile of single IV dose of ART5803 following prior doses of IVIG as measured by area under the curve from time 0 extrapolated to infinity (AUC0-∞)
To assess the pharmacokinetics (PK) of single IV dose of ART5803 following prior doses of IVIG
Time frame: 13 Weeks
To characterize and compare the PK profile of single IV dose of ART5803 following prior doses of IVIG as measured by the half-life (t½)
To assess the pharmacokinetics (PK) of single IV dose of ART5803 following prior doses of IVIG
Time frame: 13 Weeks
To characterize and compare the PK profile of single IV dose of ART5803 following prior doses of IVIG as measured by the volume of distribution (Vd)
To assess the pharmacokinetics (PK) of single IV dose of ART5803 following prior doses of IVIG
Time frame: 13 Weeks
To characterize and compare the PK profile of single IV dose of ART5803 following prior doses of IVIG as measured by by clearance (CL)
To assess the pharmacokinetics (PK) of single IV dose of ART5803 following prior doses of IVIG
Time frame: 13 Weeks
To asses the CSF/serum ratio of ART5803 at multiple time points
1 secondary outcome
To assess the immunogenicity of a single IV dose of ART5803 following prior doses of IVIG
Time frame: 13 Weeks
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 27 Apr 2026.
- 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.
Sankalp Gokhale, MD, MBA study chair
Arialys Therapeutics
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing ART5803 and Intravenous immunoglobulin (IVIG) in people with Autoimmune Encephalitis Caused by N-Methyl D-Aspartate Receptor Antibody and Autoimmune Encephalitis Caused by N-Methyl D-Aspartate Receptor Antibody (Disorder), run by Arialys Therapeutics at 1 site in Australia.
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 9 inclusion and 24 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: finished, as of the sponsor's last update on 27 Apr 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Australia. 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 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
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?
Safety will be assessed by the incidence and severity of treatment-emergent adverse events (TEAEs) (time frame: 13 Weeks). The study lists 20 primary outcomes in all. 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 27 Apr 2026; AzTrials last refreshed its copy on 8 Nov 2026.