1. Concentration-Dependent Activity of Hydromethylthionine on Clinical Decline and Brain Atrophy in a Randomized Controlled Trial in Behavioral Variant Frontotemporal Dementia
- Author
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Alison D. Murray, Christopher M. Rubino, Helen Shiells, Charles R. Harrington, Claude M. Wischik, Hans J Moebius, Damon Wischik, Thomas C. Baddeley, Gernot Riedel, John Storey, Harish Ganesan, Peter Bentham, Roger T. Staff, Bjoern Schelter, Serge Gauthier, Vesna Vuksanović, Jianping Jia, Luc Bracoud, Karin A Kook, Christopher M. Kipps, Jiri Hardlund, Jeffrey P. Hammel, Vuksanovic, Vesna [0000-0003-4655-698X], Murray, Alison D [0000-0003-4915-4847], Jia, Jianping [0000-0003-4624-0336], Kipps, Christopher M [0000-0002-5205-9712], Storey, John MD [0000-0002-5261-5467], and Apollo - University of Cambridge Repository
- Subjects
0301 basic medicine ,Male ,TDP-43 ,Gastroenterology ,law.invention ,0302 clinical medicine ,Randomized controlled trial ,law ,hydromethylthionine ,education.field_of_study ,leucomethylthioninium ,General Neuroscience ,Brain ,General Medicine ,Middle Aged ,Magnetic Resonance Imaging ,Psychiatry and Mental health ,Clinical Psychology ,Treatment Outcome ,Frontotemporal Dementia ,Disease Progression ,Female ,Research Article ,Frontotemporal dementia ,Adult ,medicine.medical_specialty ,Population ,tau protein ,03 medical and health sciences ,Atrophy ,Pharmacokinetics ,Behavioral variant frontotemporal dementia ,Double-Blind Method ,Internal medicine ,medicine ,Humans ,education ,Pathological ,Aged ,clinical trials ,Dose-Response Relationship, Drug ,business.industry ,medicine.disease ,Clinical trial ,Methylene Blue ,030104 developmental biology ,Clinical Global Impression ,Geriatrics and Gerontology ,business ,030217 neurology & neurosurgery - Abstract
Background Hydromethylthionine is a potent inhibitor of pathological aggregation of tau and TDP-43 proteins. Objective To compare hydromethylthionine treatment effects at two doses and to determine how drug exposure is related to treatment response in bvFTD. Methods We undertook a 52-week Phase III study in 220 bvFTD patients randomized to compare hydromethylthionine at 200 mg/day and 8 mg/day (intended as a control). The principal outcomes were change on the Addenbrookes Cognitive Examination - Revised (ACE-R), the Functional Activities Questionnaire (FAQ), and whole brain volume. Secondary outcomes included Modified Clinical Global Impression of Change (Modified-CGIC). A population pharmacokinetic exposure-response analysis was undertaken in 175 of the patients with available blood samples and outcome data using a discriminatory plasma assay for the parent drug. Results There were no significant differences between the two doses as randomized. There were steep concentration-response relationships for plasma levels in the range 0.3-0.6 ng/ml at the 8 mg/day dose on clinical and MRI outcomes. There were significant exposure-dependent differences at 8 mg/day for FAQ, Modified-CGIC, and whole brain atrophy comparing patients with plasma levels greater than 0.346 ng/ml with having minimal drug exposure. The exposure-response is biphasic with worse outcomes at the high concentrations produced by 200 mg/day. Conclusions Hydromethylthionine has a similar concentration-response profile for effects on clinical decline and brain atrophy at the 8 mg/day dose in bvFTD as recently reported in AD. Treatment responses in bvFTD are predicted to be maximal at doses in the range 20-60 mg/day. A confirmatory placebo-controlled trial is now planned.
- Published
- 2020