Key facts
- Design correction: participants chose not to learn their own FFI genotype, so the trial treats 10 carriers with doxycycline and gives placebo to 15 non-carriers from the same family; it is funded by Fondazione Telethon.
- Dose 100 mg per day (200 mg since June 2019) with assessments every six months; results are not yet published in the sources found (the EU register lists the trial as completed).
- Mice: doxycycline improved memory and circadian rhythm but did not delay onset or prolong survival.
- As of 2013 no drug, supplement or lifestyle measure had been shown to delay genetic prion disease.
- Modality: Oral repurposed antibiotic.
- Human data: Results not located.
- Limits: Single family; no randomised control; mouse data mixed.
Timeline
- 2011Design: carriers over 42 take 100 mg doxycycline daily for ten years, with non-carriers of the same family as the placebo group (the original design also referred to a historical dataset); randomised design not feasible.
- 2019Doxycycline dose raised to 200 mg per day in the FFI prevention trial.
- 2021FFI mice: doxycycline rescued memory and circadian deficits but did not prevent fatal disease.
Sources for this page
- Preventive pharmacological treatment in subjects at risk for FFI: science and public engagement (Prion 2022; participants and funding)
- EU Clinical Trials Register: Fatal familial insomnia, preventive treatment with doxycycline of at-risk individuals (2010-022233-28)
- Doxycycline in FFI mice (Neurobiology of Disease 2021; PMC full text)
- cureffi: Current status of efforts to delay genetic prion disease in humans (2013)
- Preventive study in subjects at risk of fatal familial insomnia (Prion 2015)
- Preventive pharmacological treatment in subjects at risk for fatal familial insomnia: science and public engagement (Prion 2022)