Abstract
Objectives There are no disease-modifying treatments that arrest or reverse tau hyperphosphorylation in tauopathies. Through its action in upregulating protein phosphatase 2 (PP2A), sodium selenate has been shown to reduce levels of total-tau, phosphorylated-tau and hyperphosphorylated-tau in animal models of disease associated with increases in tau as well as early phase clinical trials. This study is a placebo-controlled, randomised controlled trial of sodium selenate as a treatment for the primary tauopathy, progressive supranuclear palsy (PSP).
Methods 70 patients with probable PSP (Richardson’s syndrome) will be recruited, and randomised to treatment with sodium selenate (15 mg tds) or placebo (1:1) over 52 weeks. The study is recruiting at 6 sites across Australia. The primary study outcome will be change in MRI volume composite (frontal lobe+midbrain-3rd ventricle) over 52 weeks of treatment. Secondary outcome measures will include change on the PSP rating scale, clinical global impression of change, and change in midbrain mean diffusivity.
Results Presently, 19 patients have been screened, resulting in 3 screen fails, 15 randomisations and 1 awaiting randomisation. Of the 15 patients randomised, 3 have completed the study, 1 withdrew early (due to an adverse event) and 11 remain on treatment. Baseline characteristics of randomised patients are: Age median 64 years (range 47–74), male (n=10) and PSPRS total score: mean 37.4 (range 11–61). To date safety has been good with no serious adverse events related to treatment.
Conclusion Recruitment is ongoing and is expected to complete in March 2024, with last patient last visit in June 2025.
