Clinical Trial Frequently Asked Questions (FAQ)

What was the LUCIDITY trial?

LUCIDITY, which completed in April 2023, was a randomized, placebo-controlled, 2-part, 3-arm, safety, and efficacy study of hydromethylthionine, also known as HMTM (formerly known as LMTM or LMTX®), in patients with early to mild/moderate Alzheimer’s disease. The two parts comprised a 12-month double-blind phase followed by a 12-month open-label phase. The primary objective of the LUCIDITY study was to demonstrate that HMTM therapy alone, in the absence of other Alzheimer’s treatments, is effective compared to placebo in delaying the clinical progression of the disease. This was measured using standard cognitive and functional assessments. The secondary objectives included demonstrating that such therapy is effective in delaying the pathological progression of the disease. This was measured using standard MRI and PET imaging procedures.

What are phase 2 and phase 3 clinical trials?

A phase 2 clinical trial is conducted to evaluate clinical efficacy of a drug for a particular condition in hundreds of patients and to determine the common short-term side effects and risks.

A Phase 3 clinical trial is a larger trial in a wider variety of patients, which is needed to confirm the results before the regulatory authorities approve the drug for wider use. It is usual for more than one Phase 3 trial to be conducted to show how a potential drug works in a specific patient group.

How many clinical trials is TauRx currently running?

TauRx recently completed its latest phase 3 clinical trial, named LUCIDITY. The trial used cognitive assessments and FDG-PET and MR imaging to examine and assess the efficacy of its second-generation Tau Aggregation Inhibitor in delaying the progression of disease pathology in the brain. LUCIDITY was aimed at patients with mild cognitive impairment, mild, and mild to moderate Alzheimer’s disease. The treatment duration was 12 months followed by a further 12 months access to the treatment.

What makes TauRx's compound different to other drugs for Alzheimer's?

Current symptomatic therapies for Alzheimer’s disease do not affect the progress of the disease itself, but only provide a temporary boost to mental function, with no long-term benefit. TauRx’s approach is based on Tau Aggregation Inhibitors (TAIs), in which a drug acts on the abnormal tangles of tau protein that form in the brain cells of people with Alzheimer’s disease, and prevents them from forming. TauRx TAIs act on the early stage pre-tangle tau aggregates that are thought to be particularly toxic to nerve cells. To our knowledge, no company other than TauRx has a TAI in late-stage clinical development.

How do TauRx’s Tau Aggregation Inhibitors (TAIs) work?

TAIs act on the underlying cause of the disease rather than treating symptoms. In Alzheimer’s disease, tau tangles first destroy neurons critical for memory and then attack neurons in other parts of the brain as the tau aggregation process spreads from neuron to neuron throughout the brain. Tangles form first, and most severely, in the areas of the brain that are most critical for memory. TAIs work by preventing formation of the tangles that cause dementia.

Which Alzheimer’s disease patients might benefit from tau aggregation inhibitors?

TauRx initially investigated our drug in people with mild to moderate Alzheimer’s disease. Whilst initial phase 3 trials failed to meet primary endpoints, they demonstrated promising results which warranted further investigation. Further studies helped to clarify why the previous trials did not work, and so TauRx developed the LUCIDITY trial to further study the drug for patients with mild cognitive impairment, mild and mild to moderate Alzheimer’s disease. If successful, it is hoped that the experimental drug will be approved for these stages of the disease.

How has TauRx's TAI been developed?

The first-generation Tau Aggregation Inhibitor developed by TauRx was developed by scientists at the University of Aberdeen and tested in Phase 2 trials. It was a new formulation of an existing chemical entity, but created especially for the treatment of neurodegenerative disease. Our second-generation TAI has been the subject of the recent phase 3 trials. The active ingredient in our investigational drug (methylthioninium, MT) is related to an older chemical entity, methylthioninium chloride (MTC). While MTC has been used in various clinical indications for over a century, it is important to note that MTC is not equivalent to our investigational drug and has not been approved for the treatment of Alzheimer's disease. The formulation developed by TauRx for this study was specifically designed to address issues of tolerability and bioavailability that make standard MTC unsuitable for chronic oral use in neurodegenerative diseases. Patients and their caregivers should not attempt to use MTC or any other non-approved substance as a substitute for participation in clinical trials or approved treatments.

When will a TAI be available as a new medicine?

The clinical trials process, and subsequent regulatory approval processes, are long and rigorous to ensure that future therapies are thoroughly proven to be safe and effective for patients before they are made available for use. It is difficult to predict if and when a TAI will be available for prescription, but we will be able to explain this further when results of the LUCIDITY trial are available.

Do TAIs have any side effects?

All drugs can cause side effects. Until our full phase 3 study program is complete, it is not possible to define our compound’s side effect profile. Preliminary safety findings can be found in the Lancet publication, and every patient taking part in the trial is very closely monitored for any side effects of the drug.

Am I able to get this drug now through my own doctor?

Your doctor will be unable to prescribe our experimental drug for you, as it is unlicensed and is currently under investigation as a potential treatment for Alzheimer’s disease. Only when a drug has been approved by regulatory authorities and receives formal marketing authorisation can it be prescribed by physicians, as only then is it deemed safe and effective for treatment. As always, you should discuss any concerns about your health with your GP.