The National Health Service (NHS) is considering hydromethylthionine mesylate (HMTM), an oral drug developed by British firm TauRx, as a potential treatment for Alzheimer's disease. Regulators are expected to make a decision in April regarding its approval for NHS use.
Mechanism of Action and Potential Benefits
HMTM is designed to prevent the accumulation of tau protein clumps in the brain, a process believed to contribute to neuronal damage and cognitive decline in Alzheimer's disease. Unlike existing treatments like lecanemab and donanemab, which require intravenous administration, HMTM is a daily pill, potentially offering significant cost savings and convenience for patients and the NHS.
NHS officials anticipate that the at-home administration of HMTM could reduce healthcare costs associated with the bi-weekly or monthly hospital visits required for intravenous treatments. Developed from methylene blue, a compound previously used to treat malaria, HMTM represents a novel approach to targeting tau protein aggregation.
Expert Opinions and Trial Data
Professor Alistair Burns, former NHS clinical director for dementia, described the trial results as "great news," highlighting the potential of HMTM to slow the disease process. He noted that after a long period without new therapies, HMTM could be among the first of a new generation of treatments for Alzheimer's.
However, the drug's effectiveness remains a point of contention. While some trial results suggest a better safety profile compared to other treatments, concerns have been raised about the lack of published, peer-reviewed clinical trial data. One source close to the regulatory process stated that TauRx had provided limited evidence supporting the drug's efficacy, while others have pointed out that in a subset of participants with mild cognitive impairment, HMTM showed beneficial effects without the brain bleeding or swelling associated with drugs like donanemab or lecanemab.
Data presented at the Alzheimer's Disease International conference in 2024 indicated no overall benefit over placebo in terms of memory and cognitive decline, which the company attributed to unexpected placebo effects. Dr. Richard Oakley from the Alzheimer's Society emphasized the difficulty in assessing the drug's true effectiveness without peer-reviewed publication of the phase 3 study results.
Context within the Alzheimer's Treatment Landscape
The potential approval of HMTM comes after the rejection of two other Alzheimer's drugs, including lecanemab, due to cost concerns. Lecanemab, despite demonstrating a 27% slowing of cognitive decline over 18 months in trials and receiving MHRA approval, was deemed too expensive for widespread NHS use. This has raised concerns that effective treatments may only be accessible to the wealthiest individuals.
The decision by NICE regarding HMTM is eagerly awaited, as it could mark a significant turning point in the treatment of Alzheimer's disease within the NHS. The committee is scheduled to make its decision no earlier than April.
