The ExTINGUISH Trial of Inebilizumab in NMDAR Encephalitis (ExTINGUISH)
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ClinicalTrials.gov Identifier: NCT04372615 |
Recruitment Status :
Recruiting
First Posted : May 4, 2020
Last Update Posted : October 24, 2022
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Condition or disease | Intervention/treatment | Phase |
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Autoimmune Encephalitis Encephalitis | Drug: Inebilizumab Drug: Placebo | Phase 2 |
Study Type : | Interventional (Clinical Trial) |
Estimated Enrollment : | 116 participants |
Allocation: | Randomized |
Intervention Model: | Parallel Assignment |
Masking: | Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor) |
Primary Purpose: | Treatment |
Official Title: | A Phase-2b, Double-Blind, Randomized Controlled Trial to Evaluate the Activity and Safety of Inebilizumab in Anti-Nmda Receptor Encephalitis and Assess Markers of Disease |
Actual Study Start Date : | March 30, 2022 |
Estimated Primary Completion Date : | October 31, 2025 |
Estimated Study Completion Date : | August 31, 2026 |

Arm | Intervention/treatment |
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Active Comparator: Inebilizumab
Approximately 58 patients will receive Inebilizumab in addition to first line immunotherapy. (Approximately 116 participants will be randomized in a 1:1 ratio to 2 treatment groups; approximately 58 participants to each treatment group). All participants will also receive a 3 day course of IVIg. |
Drug: Inebilizumab
RCP: Blinded treatment on Day 1, Day 15,
Rescue therapy will be given to participants in either treatment group based on the results of the Week 6 assessments. Rescue therapy is cyclophosphamide 750 mg/m2 IV followed by additional doses every 28-30 days until the mRS score is ≤ 3 (at site Principal Investigator's discretion under standard of care). Other Name: UPLIZNA |
Placebo Comparator: Placebo
Approximately 58 patients will receive placebo in addition to first line immunotherapy. (Approximately 116 participants will be randomized in a 1:1 ratio to 2 treatment groups; approximately 58 participants to each treatment group). All participants will also receive a 3 day course of IVIg. |
Drug: Placebo
The placebo group will receive IV matching placebo on Day 1 and Day 15, |
- Change of modified Rankin score at 16 weeks [ Time Frame: 16 weeks ]Change in modified Rankin score (mRS) (0 to 6; 0=normal and 6=death) at 16 weeks determined by rank analyses, integrating need for rescue therapy and time to achievement of the mRS.
- Inebilizumab safety measures by the number of treatment-emergent adverse events and serious adverse events [ Time Frame: 96 weeks ]Inebilizumab safety, as measured by the number of treatment-emergent adverse events (TEAEs) and treatment-emergent serious adverse events (TESAEs)
- Time to mRS ≤ 2, corrected for baseline value. [ Time Frame: 96 weeks ]Time to mRS ≤ 2, corrected for baseline value.
- Clinical Assessment Scale in Autoimmune Encephalitis (CASE) Score (continuous logistic regression), corrected from baseline value to week 24 (weeks 6 and 16). [ Time Frame: 16 weeks ]Clinical Assessment Scale in Autoimmune Encephalitis (CASE) Score (ranges of 0 to 27 with 0 being normal and 27 being worse)(continuous logistic regression), corrected from baseline value to week 24 (weeks 6 and 16).
- mRS at week 6 as measured by proportional odds logistic regression/shift analysis. [ Time Frame: 6 weeks ]mRS at week 6 as measured by proportional odds logistic regression/shift analysis.
- Proportion of participants who meet the protocol-defined criteria for needing rescue therapy at week 6. [ Time Frame: 6 weeks ]Proportion of participants who meet the protocol-defined criteria for needing rescue therapy at week 6.
- Cognitive outcome at week 24 as measured by mean scaled score on the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) + components of Delis-Kaplan Executive Function System (D-KEFS). [ Time Frame: 24 weeks ]Cognitive outcome at week 24 as measured by mean scaled score on the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) + components of Delis-Kaplan Executive Function System (D-KEFS).
- Survival as measured by a Kaplan-Meier analysis. [ Time Frame: 96 weeks ]Survival as measured by a Kaplan-Meier analysis.

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.
Ages Eligible for Study: | 18 Years and older (Adult, Older Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | No |
Inclusion Criteria:
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Inclusion Criteria 1. Diagnosis of NMDAR encephalitis, defined by both (a) and (b):
- A subacute onset of change in mental status consistent with autoimmune encephalitis,
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A positive cell-based assay for anti-NMDA receptor IgG antibody in the CSF confirmed in study-specified laboratories.
2. Age ≥ 18 years 3. Written informed consent and any locally required authorization (e.g., Health Insurance Portability and Accountability Act [HIPAA] in the United States of America (USA), European Union [EU] Data Privacy Directive in the EU) obtained from the participant/legal representative prior to performing any protocol-related procedures, including screening evaluations.
4. Females of childbearing potential who are sexually active with a nonsterilized male partner must agree to use a highly effective method of contraception beginning at screening or upon discharge from hospitalization/inpatient rehabilitation (for participants who were incapacitated at the time of screening), and to continue precautions for 6 months after the final dose of investigational product.
5. Nonsterilized males who are sexually active with a female partner of childbearing potential must agree to use a highly effective method of contraception at screening or upon discharge from hospitalization/inpatient rehabilitation (for participants who were incapacitated at the time of screening), and to continue precautions for 3 months after the final dose of investigational product. Male patients with female partners of childbearing potential must have that female partner use at least one form of highly effective contraception, starting at least one menstrual cycle before (the male patient's) first study drug administration and continuing until at least 3 months after their male partner's last dose of the study drug.
6. Willing to forego other immunomodulatory therapies (investigational or otherwise) for NMDAR encephalitis during the study.
7. Patient must have received at least 3 days of methylprednisolone 1000 mg IV or equivalent corticosteroid within 30 days prior to randomization (Day 1). In addition, patients must have received EITHER of the following treatments within 30 days before randomization.
- IVIg, at a minimum dose of 2 g/kg
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Plasma exchange or plasmapheresis, with a minimum of 5 treatments. NOTE: These treatments may be provided during the screening period, but must be completed prior to randomization.
8. mRS of ≥3 at the screening visit, indicating at least moderate disability. 9. Ability and willingness to attend study visits and complete the study
Exclusion Criteria:
- Any condition that, in the opinion of the investigator, would interfere with the evaluation or administration of the investigational product, interpretation of participant safety or study results, or would make participation in the study an unacceptable risk. This specifically includes recent history (last 5 years) of herpes simplex virus encephalitis or known central nervous system demyelinating disease (e.g., multiple sclerosis).
- Presence of an active or chronic infection that is serious in the opinion of the investigator.
- Concurrent/previous enrollment in another clinical study involving an investigational treatment within 4 weeks or 5 published half-lives of the investigational treatment, whichever is the longer, prior to randomization.
- Lactating or pregnant females, or females who intend to become pregnant anytime from study enrollment to 6 months following last dose of investigational agent.
- Known history of allergy or reaction to any component of the investigational agent formulation or history of anaphylaxis following any biologic therapy.
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At screening (one repeat test may be conducted to confirm results prior to randomization within the same screening period), any of the following:
- Aspartate transaminase (AST) > 2.5 × upper limit of normal (ULN)
- Alanine transaminase (ALT) > 2.5 × upper limit of normal (ULN)
- Total bilirubin > 1.5 × ULN (unless due to Gilbert's syndrome)
- Platelet count < 75,000/μL (or < 75 × 109/L)
- Hemoglobin < 8 g/dL (or < 80 g/L)
- Total white blood count <2,500 cells/mm3
- Total immunoglobulin < 600 mg/dL
- Absolute neutrophil count < 1200 cells/μL
- CD4 T lymphocyte count < 300 cells/µL
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Receipt of the following at any time prior to randomization:
- Alemtuzumab
- Total lymphoid irradiation
- Bone marrow transplant
- T-cell vaccination therapy
- Receipt of rituximab or any experimental B-cell depleting agent, unless the CD19 B-cell level has returned to above the lower limit of normal prior to randomization.
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Receipt of any of the following within 3 months prior to randomization
- Natalizumab (Tysabri®)
- Cyclosporine
- Methotrexate
- Mitoxantrone
- Cyclophosphamide
- Azathioprine
- Mycophenolate mofetil
- Severe drug allergic history or anaphylaxis to two or more food products or medicines (including known sensitivity to acetaminophen/paracetamol, diphenhydramine or equivalent antihistamine, and methylprednisolone or equivalent glucocorticoid).
- Known history of a primary immunodeficiency (congenital or acquired) or an underlying condition such as human immunodeficiency virus (HIV) infection or splenectomy that predisposes the participant to infection.
13. Confirmed positive test for hepatitis B serology (hepatitis B surface antigen and core antigen) and/or hepatitis C PCR positive at screening.
14. History of cancer, apart from ovarian or extra-ovarian teratoma (also known as a dermoid cyst) or germ cell tumor, or 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.
15. Any live or attenuated vaccine within 3 weeks prior to Day 1 (administration of killed vaccines is acceptable).
16. Bacillus of Calmette and Guérin (BCG) vaccine within 1 year of enrollment. 17. Recurrence of previously treated NMDAR encephalitis within the last 3 or 5 years, or suspicion of symptomatic untreated NMDAR encephalitis of greater than 3 months duration at the time of screening.

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT04372615
Contact: Stacey L Clardy, MD, PhD | 8015857575 | stacey.clardy@hsc.utah.edu | |
Contact: Ka-Ho Wong, MBA | 8015857575 | ka-ho.wong@hsc.utah.edu |

Principal Investigator: | Stacey L Clardy, MD, PhD | University of Utah |
Responsible Party: | Stacey Clardy MD PhD, Associate Professor, University of Utah |
ClinicalTrials.gov Identifier: | NCT04372615 |
Other Study ID Numbers: |
143461 |
First Posted: | May 4, 2020 Key Record Dates |
Last Update Posted: | October 24, 2022 |
Last Verified: | October 2022 |
Individual Participant Data (IPD) Sharing Statement: | |
Plan to Share IPD: | No |
Plan Description: | Data from this study will only be shared with the researchers and organizations listed in the application and consent form. Participants can opt to have their excess biosamples banked as part of an optional substudy. Any samples shared in the future will be deidentified. |
Studies a U.S. FDA-regulated Drug Product: | Yes |
Studies a U.S. FDA-regulated Device Product: | No |
Inebilizumab NMDAR encephalitis Autoimmune Encephalitis Rare Disease |
Encephalitis Brain Diseases Central Nervous System Diseases Nervous System Diseases |