Safety and Efficacy Study Evaluating TRx0237 in Subjects With Mild Alzheimer's Disease

Inclusion Criteria:

• Diagnosis of all cause dementia and probable Alzheimer's disease

• Clinical Dementia Rating (CDR) total score of 0.5 or 1 (mild) and MMSE score of 20-26 (inclusive)

• Age <90 years

• Modified Hachinski ischemic score of ≤4

• Females, if of child-bearing potential, must practice true abstinence or be competentto use adequate contraception and agree to maintain this throughout the study

• Subject, and/or, in the case of reduced decision-making capacity, legally acceptablerepresentative(s) consistent with national law is/are able to read, understand, andprovide written informed consent

• Has one (or more) identified adult caregiver who is willing to provide writteninformed consent for his/her own participation; is able to read, understand, and speakthe designated language at the study site; either lives with the subject or sees thesubject for ≥2 hours/day ≥3 days/week; agrees to accompany the subject to each studyvisit; and is able to verify daily compliance with study drug

• If currently taking an acetylcholinesterase inhibitor and/or memantine at the time ofScreening, the subject must have been taking such medication(s) for ≥3 months. Thedosage regimen must have remained stable for ≥6 weeks and it must be planned to remainstable throughout participation in the study.

• Able to comply with the study procedures

Exclusion Criteria:

• Significant central nervous system (CNS) disorder other than Alzheimer's disease

• Significant focal or vascular intracranial pathology seen on brain MRI scan

• Clinical evidence or history of stroke, transient ischemic attack, significant headinjury or other unexplained or recurrent loss of consciousness ≥15 minutes

• Epilepsy

• Major depressive disorder, schizophrenia, or other psychotic disorders, bipolardisorder, substance (including alcohol) related disorders

• Metal implants in the head (except dental), pacemaker, cochlear implants, or any othernon-removable items that are contraindications to MRI

• Resides in hospital or moderate to high dependency continuous care facility

• History of swallowing difficulties

• Pregnant or breastfeeding

• Glucose-6-phosphate dehydrogenase deficiency

• History of significant hematological abnormality or current acute or chronicclinically significant abnormality

• Abnormal serum chemistry laboratory value at Screening deemed to be clinicallyrelevant by the investigator

• Clinically significant cardiovascular disease or abnormal assessments

• Preexisting or current signs or symptoms of respiratory failure

• Concurrent acute or chronic clinically significant immunologic, hepatic, or endocrinedisease (not adequately treated) and/or other unstable or major disease other thanAlzheimer's disease

• Diagnosis of cancer within the past 2 years prior to Baseline (other than basal cellor squamous cell skin cancer or Stage 1 prostate cancer) unless treatment has resultedin complete freedom from disease for at least 2 years

• Prior intolerance or hypersensitivity to methylthioninium-containing drug, similarorganic dyes, or any of the excipients

• Treatment currently or within 3 months before Baseline with any of the followingmedications (unless otherwise noted):

• Tacrine

• Clozapine, olanzapine (and there is no intent to initiate therapy during thecourse of the study)

• Carbamazepine, primidone

• Drugs with a warning or precaution in the labeling of methemoglobinemia atapproved doses

• Current or prior participation in a clinical trial as follows:

• Clinical trial of a product for cognition in which the last dose was receivedwithin 90 days prior to Screening (unless confirmed to have been randomized toplacebo)

• A clinical trial of a drug, biologic, device, or medical food in which the lastdose/administration was received within 28 days prior to Baseline