Efficacy and Safety of Calculus Bovis Sativus (CBS) for Adult Encephalitis (CBSinEncephalitis)

Inclusion Criteria:

• Subjects must meet the following eligibility criteria at screening to participate inthis study.

1.1 Inclusion criteria for subjects with autoimmune encephalitis (hereinafter referred to as AE) of all subtypes 1.1.1 Subjects are able to understand the purpose and risks of the study, provide informed consent, and authorize the use of confidential health information in accordance with national and local privacy regulations.

1.1.2. Tumors or malignancies can be reasonably excluded before the baseline visit (randomization), and screening guidelines for thymoma, teratoma, and malignant tumors should be followed.

1.1.3. Both men and women are welcome, and the age at the time of providing informed consent is 18-80 years old (inclusive).

1.1.4. Meet the diagnosis of AE (according to the Chinese Autoimmune Encephalitis Diagnosis and Treatment Expert Consensus 2022 Edition): A. Clinical manifestations: acute or subacute onset (<3 months), with one or more of the following neurological and psychiatric symptoms or clinical syndromes.

• a. Limbic system symptoms: recent memory loss, epileptic seizures, mental andbehavioral abnormalities, one or more of the three symptoms.

• b. Encephalitis syndrome: clinical manifestations of diffuse or multifocal braindamage.

• c. Clinical manifestations of involvement of the basal ganglia and/ordiencephalon/hypothalamus.

• d. Mental disorder, and the psychiatric specialist believes that it does not meetthe non-organic disease.

B. Auxiliary examination: one or more of the following auxiliary examination findings, or combined with related tumors.

• a. Abnormal cerebrospinal fluid: cerebrospinal fluid leukocytosis (>5×106/L), orcerebrospinal fluid cytology shows lymphocytic inflammation, or specific oligoclonalbands are positive.

• b. Neuroimaging or electrophysiological abnormalities: MRI limbic system T2 or FLAIRabnormal signals, unilateral or bilateral, or other areas of T2 or FLAIR abnormalsignals (excluding nonspecific white matter changes and stroke); or PET imaginglimbic system hypermetabolism changes, or multiple cortical and/or basal gangliahypermetabolism. Figure 1 shows the typical neuroimaging manifestations of AEpatients. Abnormal electroencephalogram, manifested as focal epilepsy orepileptiform discharge (located in the temporal lobe or outside the temporal lobe),or diffuse or multifocal slow wave rhythm. In adult patients with anti-NMDARencephalitis, abnormal delta brush waves (extreme delta brush) often correspond toprolonged hospitalization and poor prognosis.

• c. Specific types of tumors associated with AE, such as limbic encephalitis combinedwith small cell lung cancer, anti-NMDAR encephalitis combined with ovarian teratoma.

C. Confirmatory experiments: positive anti-neuronal antibodies. Including NMDA-R, LGI-1, CASPR2, IgLON5, GABAA/BR, GlyR, AMPAR and axonal protein-3α and intracellular substance antibodies anti-Hu, anti-Ma2, anti-CRMP5, anti-Yo, anti-double carrier protein, anti-GAD, etc.

D. Reasonably exclude other causes (refer to the differential diagnosis section of the consensus).

Diagnostic criteria: including possible AEs and confirmed AEs:

1. Possible AEs: meet the three diagnostic criteria of A, B and D.

2. Confirmed AEs: meet the four diagnostic criteria of A, B, C and D. 1.1.5. AEsymptoms occurred ≤9 months before randomization 1.1.6. Subjects meet new AEs

• New onset: defined as subjects with NMDA-R or LGI-1 AEs and meeting thefollowing criteria:

• The mRS score measured at baseline is stable (at least 24 hours) and is ≥2points.

• Received the first acute first-line treatment within 6 weeks beforerandomization (baseline visit).

1.1.7. All females of childbearing potential and all males must use contraceptionduring the study and for at least 30 days after the last dose of study treatment. Inaddition, subjects should not donate sperm or eggs during the study and for at least 30 days after the last dose of study treatment.

1.1.8. Stable neurological examination within 30 days before baseline (Visit 1).

1.2 Additional inclusion criteria for the NMDA-R AE cohort In addition to the criteria outlined in Section 1.1, only subjects who met all ofthe following criteria were eligible for inclusion in the NMDA-R AE cohort:

• Age ≥ 18 years at the time of informed consent

• Informed consent, as appropriate based on patient age, specific site, andnational criteria

• Suspected or definite NMDAR AE diagnosis as follows:

1.2.1. Suspected NMDAR encephalitis was diagnosed when all three of the followingcriteria were met: 1.2.1.1 Rapid onset (less than 3 months) of at least four of thefollowing six cardinal symptoms:

• Abnormal (psychiatric) behavior or cognitive dysfunction

• Speech dysfunction (rushing speech, hypospeech, mutism)

• Seizures

• Ataxia, dyskinesia, or rigid/abnormal posture

• Decreased level of consciousness

• Autonomic dysfunction or central hypoventilation 1.2.1.2. At least one of thefollowing laboratory results:

• Abnormal EEG (focal or diffuse slow or disorganized activity, epilepticactivity, or extreme delta brushes)

• CSF with pleocytosis or oligoclonal bands 1.2.1.3. Reasonable exclusion ofother etiologies and other clear encephalitis syndromes: for example,Bickerstaff brainstem encephalitis, acute disseminated encephalomyelitis,Hashimoto encephalopathy, primary angiitis of the central nervous system (CNS),Rasmussen encephalitis. Note: If the above three groups of symptoms in criterion 1.2.1.1 are present andaccompanied by systemic teratoma, suspected NMDAR encephalitis can also bediagnosed.

1.2.2 Definite NMDAR encephalitis can be diagnosed when the following three criteriaare met at the same time: 1.2.2.1. The presence of one or more of the six mainsymptoms described in criterion 1.2.1.1 for suspected NMDAR encephalitis.

1.2.2.2. History of anti-NMDAR (GluN1) IgG antibodies detected in CSF using acell-based assay.

1.2.3. Reasonable exclusion of other etiologies and other well-defined encephalitissyndromes: e.g., Bickerstaff brainstem encephalitis, acute disseminatedencephalomyelitis, Hashimoto encephalopathy, primary angiitis of the central nervoussystem (CNS), Rasmussen encephalitis.

1.3 Other inclusion criteria for the LGI-1 AE cohort In addition to the criteria outlined in Section 1.1, only subjects who meet all ofthe following criteria are eligible for inclusion in the LGI1 AE cohort:

1.3.1 Age ≥ 18 years at the time of signing the informed consent For subjects whoare unable to provide informed consent due to the severity of their illness, theinformed consent may be signed by their legally authorized representative at thetime of obtaining the subject's consent, according to local requirements.

1.3.2 Diagnosis of LGI-1 AE The diagnosis of LGI-1 encephalitis can be made when both of the following criteriaare met:

1.3.2.1 Documented history of anti-LGI-1 IgG antibodies (in serum or CSF) using acell-based assay.

1.3.2.2 Subacute onset (less than 4 months of development) of working memorydeficits, seizures (including faciobrachial dystonic seizures), or psychiatricsymptoms suggestive of limbic system involvement.

1.3.2.3 Diagnosis of LGI1 AE is reasonable when other etiologies and otherwell-defined encephalitis syndromes are excluded: e.g., Bickerstaff brainstemencephalitis, acute disseminated encephalomyelitis, Hashimoto encephalopathy,primary CNS vasculitis, Rasmussen encephalitis.

1.4 Other inclusion criteria for the AA AE cohort In addition to the criteria outlined in Section 1.1, only subjects who meet all ofthe following criteria are eligible for inclusion in the AA AE cohort:

• Aged ≥ 18 years at the time of signing the informed consent form For subjectswho are unable to provide informed consent due to the severity of theirillness, the informed consent form may be signed by their legally authorizedrepresentative when the subject agrees, according to local requirements.

• Diagnosis of AA AE Meet the diagnosis of AE in 1.1, negative for anti-NMDAantibodies and anti-LGI-1 antibodies, and positive for at least one of theother anti-neuronal antibodies.

1.5 Inclusion criteria for viral encephalitis (hereinafter referred to as VE) cohort The following four conditions must be met simultaneously for diagnosis of VE:

• Primary condition: altered mental status, including decreased level ofconsciousness, drowsiness, or abnormal mental behavior lasting ≥24 h; or newonset of epileptic seizure

• Secondary condition: fever ≥38 °C (before or within 72 h after onset), or newfocal manifestations of the nervous system, or cerebrospinal fluid leukocytes ≥5×10^6/L, or cerebrospinal fluid cytology showing lymphocytic inflammation, orimaging showing brain parenchymal lesions consistent with encephalitis, orabnormal electroencephalogram consistent with encephalitis

• Confirmatory laboratory test: positive cerebrospinal fluid viral nucleic acid (polymerase chain reaction or metagenomic next-generation sequencing), orpositive cerebrospinal fluid and/or serum antiviral antibody IgM

• Reasonable exclusion of other causes

1.6 Healthy cohort:

• Age ≥ 18 years old when signing the informed consent form

• Healthy adult subjects without underlying diseases

• Exclusion Criteria:
• Any clinically significant cardiac, endocrine, hematologic, hepatic,immune, infectious, metabolic, urologic, pulmonary, neurological,dermatologic, psychiatric, and renal disease or other major medicalhistory that the investigator determines would preclude participationin the clinical trial.
• Any untreated teratoma or thymoma at the baseline visit (randomization)
• Other causes of symptoms, including central nervous system infection,septic encephalopathy, metabolic encephalopathy, epileptic disorders,mitochondrial disease, Klein-Levin syndrome, Creutzfeldt-Jakobdisease, rheumatic disease, Reyes syndrome, or inborn errors ofmetabolism.
• History of herpes simplex encephalitis within the previous 24 weeks. 1.5. Any surgical procedure within 4 weeks prior to baseline, exceptlaparoscopic surgery or minor surgery (defined as surgery requiringonly local anesthesia or conscious sedation, i.e., surgery that doesnot require general, neuraxial, or regional anesthesia and can beperformed on an outpatient basis; e.g., toenail surgery, molesurgery, wisdom tooth extraction), excluding thymoma or teratomaremoval.
• Planned surgery during the study (except minor surgery).
• History of severe allergic or anaphylactic reactions, or any allergicreaction that the investigator believes may be exacerbated by anycomponent of study treatment.
• Current or history of malignant disease, including solid tumors andhematologic malignancies (except for basal cell carcinoma andsquamous cell carcinoma that have been completely resected andconsidered cured for at least 12 months prior to Day -1). Subjectswith cancer remission for more than 5 years prior to baseline (Visit

1. may be included after discussion with the sponsor/sponsorapproval.

• A history of gastrointestinal surgery (except appendectomy orcholecystectomy performed more than 6 months before screening),irritable bowel syndrome, inflammatory bowel disease (Crohn'sdisease, ulcerative colitis), or other clinically significant activegastrointestinal diseases in the opinion of the investigator.
• A history of clinically significant recurrent or activegastrointestinal symptoms (e.g., nausea, diarrhea, dyspepsia,constipation) within 90 days before screening, including the need tostart symptomatic treatment (e.g., start medication forgastroesophageal reflux disease) or a change in symptomatic treatmentwithin 90 days before screening (e.g., dose increase).
• A history of diverticulitis or concurrent severe gastrointestinal (GI) abnormalities (e.g., symptomatic diverticular disease) becausethe investigator believes that this may lead to an increased risk ofcomplications such as GI perforation.
• A history of blood donation (1 unit or more), plasma donation, orplatelet donation within 90 days before screening.
• Active suicidal ideation within 6 months before screening, or ahistory of suicide attempt within 3 years before screening.
• Based on the investigator's judgment, there are serious diseases orabnormalities in the clinical laboratory test results that preventthe patient from completing the study or participating in the studysafely.
• Pregnant or lactating, or planning to become pregnant during thestudy or within 3 months after the last dose of the study drug; womenof childbearing potential must have a negative serum pregnancy testresult at screening and a negative urine pregnancy test result beforethe start of the study.
• The subject's mental or physical condition will hinder the evaluationof efficacy and safety.
• Systolic blood pressure >150 mmHg or <90 mmHg after sitting still for 5 minutes or before dosing at screening. If out of range, it can bemeasured again at screening and before dosing. If the repeatedmeasurement value is still out of range, the subject shall notreceive the drug.
• Subjects with second or third degree atrioventricular block or sicksinus syndrome, poorly controlled atrial fibrillation, severe orunstable angina, congestive heart failure, myocardial infarction, orsignificant ECG abnormalities, including corrected QT interval >450msec (male) or 470 msec (female), where corrected QT interval isdetermined based on the Fridericia correction method, within 3 monthsprior to the screening visit.
• Planned elective procedures or surgeries at any time after signingthe Informed Consent Form by follow-up visit.
• Any condition that affects the absorption of study treatment (e.g.,gastrectomy).
• History of hypersensitivity to heparin or history of heparin-inducedthrombocytopenia.
• Subjects with abnormalities in medical history, physical examination,ECG, or diagnostic laboratory tests that the investigator considersto be clinically relevant.
• History of human immunodeficiency virus (HIV) or positive testresults at screening.
• Current infection with hepatitis C (defined as positive hepatitis Cvirus (HCV) antibodies and detectable HCV RNA). Subjects withpositive HCV antibodies and HCV RNA below the limit of detection areeligible to participate in the study.
• Current infection with hepatitis B (defined as positive HBsAg and/orpositive total anti-HBc).
• Chronic, recurrent, or severe infection (e.g., pneumonia, sepsis)within 90 days prior to baseline (visit 1).
• History of tuberculosis (TB) diagnosis or positive latent TB testresult.
• Symptoms of bacterial, fungal, or viral infection (including upperrespiratory tract infection) within 28 days prior to baseline (visit 1). Subjects with localized fungal infection (e.g., candidiasis,tinea) are eligible for rescreening after successful treatment of theinfection.
• Infection requiring hospitalization or IV anti-infective medicationwithin 4 weeks prior to baseline visit.
• Any live or live attenuated vaccine within 28 days prior to baseline (visit 1) or planned during the study.
• Contraindications to all of the following salvage therapies:rituximab, intravenous immunoglobulin, high-dose corticosteroids, orIV cyclophosphamide.
• History of or receipt of the following treatments: Total lymphoidirradiation, cladribine, T-cell or T Cell recipient vaccination,total body irradiation, or total lymphoid irradiation at any time.Stem cell transplantation at any time.
• Abnormal laboratory values determined by the investigator to beclinically significant at Screening or Baseline (Visit 1).
• Any of the following blood test abnormalities at Screening: a. Whiteblood cell count < 3.0 × 10^3/µL. b. Absolute neutrophil count < 2.0 × 10^3/µL. c. Absolute lymphocyte count < 0.5 × 10^3/µL. d. Plateletcount < × 10 × 10^4/µL. e. glutamic-pyruvic transaminase, glutamicoxaloacetic transaminase, or γ-glutamyl transpeptidase ≥ 3 x upperlimit of normal (ULN) or bilirubin > 2 x ULN. f. glomerularfiltration rate ≤ 60 mL/min/1.73 m2. g. Lymphocyte count < lowerlimit of normal
• Any of the following urine test abnormalities at Screening: a. β-2-microglobulin>0.3 μg/mL. b. Albumin/creatinine ratio>22.6mg/mmol.
• Previous participation in this study.
• Blood donation (1 unit or more) within 90 days before screening,plasma donation within 1 week before screening, and platelet donationwithin 6 weeks before screening.
• History of alcohol or drug abuse in the past year (determined by theinvestigator).
• Pregnant or lactating subjects, as well as subjects planning tobecome pregnant or start breastfeeding at any time during the studyand within 30 days after completion of study treatment.
• Participating in a clinical trial or having participated in aclinical trial within 90 days before screening.
• History of clinically significant suicidal thoughts or behaviors inthe past 12 months as assessed by Columbia-Suicide Severity RatingScale at screening.
• Unwilling or unable to comply with protocol requirements.
• The patient has obvious hearing or vision impairment, languagebarriers, claustrophobia, etc., which makes the patient unable tocooperate with the neuropsychological scale assessment and MRIexamination.
• The researcher or sponsor believes that there are other unknownreasons that make the subject unsuitable for inclusion.