Safety and Efficacy Study Evaluating TRx0237 in Subjects With Behavioral Variant Frontotemporal Dementia (bvFTD)

Inclusion Criteria:

- Diagnosis of probable bvFTD

- Centrally rated frontotemporal atrophy score of 2 or greater on brain MRI

- MMSE ≥20

- Age <80 years

- Modified Hachinski ischemic score of ≤ 4

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

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

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

- If currently taking an acetylcholinesterase inhibitor and/or memantine, the subject
must have been taking such medication(s) for ≥3 months. The dosage regimen must have
remained stable for ≥6 weeks and it must be planned to remain stable throughout
participation in the study.

- Able to comply with the study procedures

Exclusion Criteria:

- Significant central nervous system (CNS) disorder other than bvFTD

- Significant intracranial pathology seen on brain MRI scan

- Biomarker evidence of underlying Alzheimer's disease pathology

- Expressive language deficits

- Meets research criteria for Amyotrophic Lateral Sclerosis or motor neuron disease

- Meets diagnostic criteria for probable bvFTD but has a proven mutation producing
non-tau, non-TDP-43 pathology

- Clinical evidence or history of stroke, transient ischemic attack, significant head
injury or other unexplained or recurrent loss of consciousness ≥15 minutes

- Epilepsy

- Rapid eye movement sleep behavior disorder

- Major depressive disorder, schizophrenia, or other psychotic disorders, bipolar
disorder, substance (including alcohol) related disorders

- Metal implants in the head (except dental), pacemaker, cochlear implants, or any other
non-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 chronic
clinically significant abnormality

- Abnormal serum chemistry laboratory value at Screening deemed to be clinically
relevant 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 endocrine
disease (not adequately treated) and/or other unstable or major disease other than
bvFTD

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

- Prior intolerance or hypersensitivity to methylthioninium-containing drug, similar
organic dyes, or any of the excipients

- Treatment currently or within 90 days before Baseline with any of the following
medications (unless otherwise noted):

- Tacrine

- Amphetamine or dexamphetamine

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

- Carbamazepine, primidone

- Drugs for which there is a warning or precaution in the labeling about
methemoglobinemia at approved doses

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

- Clinical trial of a product for cognition within 3 months of Screening (unless
confirmed to have been randomized to placebo)

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