Status and rationale of selected compounds targeting various tau proteins tested in AD clinical trials

Invested agent nameTarget and RationaleStatus on clinical trial
(start date–end date)
AD stageResultsClinical trial identifier (NCT number)
ABT-957 (Alicapistat)Inhibition of calcium-dependent cysteine protease, calpain, which is linked to hyperphosphorylation of tau and its aggregationPhase 1, (2014–2016)Mild to moderateNot reaching the effective level in CNS [25]02220738
Semorinemab, RO7105705, RG6100IgG4 antibodies targeting all 6 isoforms of extracellular tau (eTau)Phase 2, (2021)Mild/ProdromalThe primary endpoint not met didn’t show benefit or modulation of the tau-PET signal03289143
Phase 2, (2023)Probable AD and moderatePromising results on cognition03838747
BIIB092,
Gosuranemab
hmAB against eTauPhase 1/2, (2018–2021)MildLack of efficacy03352557
Zagotenemab, LY3303560hmAB against a conformational epitope of eTauPhase 1/2, (2016–2021)Mild or early symptomaticMissed primary endpoints03518073
RG7345,
RO6426496
Rabbit monoclonal Ab targeting phosphorylated Tau (at serine 422)Phase 1, (2015)Healthy malesTerminated, unfavorable phamacokinetic profile02281786
BIIB076,
NI-105
Human recombinant monoclonal anti-tau Ab targeting mid-domain of TauPhase 1 (2017–2020)Healthy and mildDiscontinued due to business reasons03056729
AADvac1Active vaccine using a synthetic tau peptidePhase 1
(2013–2015)
Phase 2
(2016–2019)
Mild to moderateSafe [26]
and promising, but lack efficacy [27]
01850238
02579252

AD: Alzheimer’s disease; hmAB: human immunoglobulin monoclonal antibody