Experimental pill for rare nerve disease shows early promise in tiny trial

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Patients must meet the NMOSD diagnostic criteria set by the international NMO Diagnostic Group (IPND) in 2015. * Serum AQP4-IgG positive. * Clinical evidence of at least 2 documented relapse (including first attack) in the last 2 years, with at least 1 relapse within 12 months prior to screening. * Extended Disability Status Scale (EDSS) score ≤7.5 at screening. * Age 18 to 75 years inclusive, weight at least 35 kg at the time of informed consent. * If the patients were using the following baseline treatment for relapse prevention, they must be treated at a steady dose for at least 4 weeks prior to enrollment: * Azathioprine, metecophenol ester and other immunosuppressive agents * Oral corticosteroid (≦30mg/ day prednisone tablet or equivalent dose of other hormones) * (patients or their legal representatives) can provide written informed consent indicating that they understand and agree to comply with the requirements of the study protocol. Exclusion Criteria: * Continuous treatment with strong or moderate CYP3A inhibitors or inducers is required during the study period. Patients were excluded if they had taken a potent or moderate CYP3A inhibitor or inducer within 7 days prior to administration of the study drug (or had stopped taking these drugs for less than 5 half-lives). * Previously treated with BTK inhibitors (e.g., ibrutinib). * Allergic to the study drug or any of the ingredient. * Desease relaps (including first episode) within the previous 30 days. * Pregnancy or lactation. * Previous or current malignancy, except locally recurrent cancers that have received radical treatment (e.g. excised basal or squamous cell skin cancer, cervical or breast cancer in situ). * Currently central nervous system (CNS) disease that may affect the evaluation of NMOSD. * Serious and uncontrolled conditions considered by the investigator that could affect safety, compliance and endpoint evaluation, or need for use of a drug not permitted in the protocol. * Disease that could affected drug absorption, distribution, metabolism, and excretion determined by the investigator. * Any major clinical infection lead to hospitalization or parenteral antibiotic treatment within 1 month prior to screening; Or other infections that may be aggravated due to the study determined by the investigator. * Active, latent or undertreated mycobacterium tuberculosis (TB) infection * Known primary immunodeficiency or underlying disease such as human immunodeficiency virus (HIV) infection. * Hepatitis B or C virus infection by serological test. * Received B-cell targeted therapy (e.g. Rituximab) within 6 months prior to the initial administration of the study drug. * Received biologics such as tozizumab within 12 weeks prior to initial administration of the study drug. * Received live attenuated vaccine during the screening and study periods, or any live virus vaccine within 8 weeks prior to initial administration. * Abnormal and clinically significant in ECG examination during screening. * Uncontrolled hypertension (SBP\>160 mmHg or DBP ≥ 95 mmHg) * Grade 3 or 4 heart Failure, (NYHA scale). * Severe liver insufficiency (Child-pugh C). * Aspartate aminotransferase (AST)\>3 times the upper limit of normal (ULN) and/or alanine aminotransferase (ALT)\>3ULN and/or bilirubin \>2ULN. * Estimated creatinine clearance \<30 mL/min or requiring dialysis. * Inability to receive MRI scans * A history of clinically significant CNS trauma * Received experimental drug or other experimental treatment within 4 weeks prior to screening or during 5 pharmacokinetic half-lives or duration of biological effects, whichever is longer. * Participate in another clinical study. * Accept any of the following: * BCG vaccination within 1 year prior to screening. * Prior bone marrow transplant, hematopoietic stem cell transplant, or systemic radiation therapy. * Received intravenous gamma globulin within 30 days prior to screening. * Plasmapheresis or leukocyte separation within 90 days prior to screening * Abnormal white blood cell count, neutrophil count, lymphocyte count, or platelet count during the screening and were considered unsuitable for study by investigator * Inability to swallow capsules or medical conditions that significantly affect gastrointestinal function * A history of severe hemorrhagic disorders such as hemophilia A, hemophilia B, von willebrand disease, or a history of spontaneous bleeding requiring blood transfusion or other medical intervention. * History of stroke or intracranial hemorrhage within 6 months prior to screening * Current alcohol, drug or chemical abuse, or history of such abuse within 1 year prior to screening. * Anticoagulants or a combination of anticoagulants and antiplatelet agents is ongoing or planned. * Any other circumstances in which the investigator or sponsor considers the patient unsuitable for study participation.