Targeting the p75 Receptor to Inhibit Degenerative Signaling and Tau Phosphorylation/Misfolding/ Missorting: Preclinical through Phase 1

Transcription

1 Targeting the p75 Receptor to Inhibit Degenerative Signaling and Tau Phosphorylation/Misfolding/ Missorting: Preclinical through Phase 1 ADC Directors Meeting, April 18 th 2015 Frank M. Longo, Stanford University UNC/UCSF Stanford Also: Steve Massa, MD, PhD at UCSF Academic/mechanistic studies ADDF Alzheimer s Association NIA U01 NINDS R21 Taube Family Koret Fdn Jean Perkins Fdn Horngren Family

2 Other factors: age, inflammation amyloid receptors Ca 2+ /Ox mito membrane effects Rho A PKA calpain MLK p-cofilin p-creb cdk5 p38 GSK3β JNK AKT p-tau / mf-tau / tau-o / ml-tau p-fyn Synaptic dysfunction Spine loss Neurite degeneration p-nr2b

3 Other factors: age, inflammation amyloid prongf/ngf p75 receptors Ca 2+ /Ox mito membrane effects Rho/GDI Death adaptors Survival adaptors Rho A PKA calpain MLK PI3K p-cofilin p-creb cdk5 p38 GSK3β JNK AKT p-tau / mf-tau / tau-o / ml-tau p-fyn Synaptic dysfunction Spine loss Neurite degeneration p-nr2b

4 Other factors: age, inflammation amyloid p75 receptors Ca 2+ /Ox mito membrane effects Rho/GDI Death adaptors Survival adaptors Rho A PKA calpain MLK PI3K p-cofilin p-creb cdk5 p38 GSK3β JNK AKT p-tau / mf-tau / tau-o / ml-tau p-fyn Synaptic dysfunction Spine loss Neurite degeneration p-nr2b

5 Aβ-induced degeneration is p75 dependent oligomeric-aβ + 21 div HC neurons p75+/+ p75+/+ dystrophic neurites (APP IHC) APP-L/S X p75 -/- p75-/- P75-/- mean differential angle CM *** *** CM Aβ1-42 Aβ1-42 p75 +/+ p75 -/- p75 enables Aβ-induced degeneration Knowles et al, J Neurosci 2009 Coulson Lab 2009 Bartlett Lab 2015

6 Other factors: age, inflammation amyloid prongf/ngf p75 receptors Ca 2+ /Ox mito membrane effects Rho/GDI Death adaptors Survival adaptors Rho A PKA calpain MLK PI3K p-cofilin p-creb cdk5 p38 GSK3β JNK AKT p-tau / mf-tau / tau-o / ml-tau p-fyn Synaptic dysfunction Spine loss Neurite degeneration p-nr2b

7 Signaling effects: Other factors: age, inflammation amyloid p75 receptors Ca 2+ /Ox mito membrane effects Rho/GDI Death adaptors Survival adaptors Rho A PKA calpain MLK PI3K p-cofilin p-creb cdk5 p38 GSK3β JNK AKT p-tau / mf-tau / tau-o / ml-tau p-fyn Synaptic dysfunction Spine loss Neurite degeneration p-nr2b

8 Signaling effects: Other factors: age, inflammation amyloid p75 Massa et al J Neurosci 2006 receptors Ca 2+ /Ox mito membrane effects Rho/GDI Death adaptors Survival adaptors Rho A PKA calpain MLK PI3K p-cofilin p-creb cdk5 p38 GSK3β JNK AKT p-tau / mf-tau / tau-o / ml-tau p-fyn Synaptic dysfunction Spine loss Neurite degeneration p-nr2b

9 LM11A-31 inhibits Aβ-induced dystrophy CM Aβ 1-42 Aβ ligand (100 nm) E17 div 21 matured hippocampal neurons % of neurites CM Aβ + C Aβ Modified from Yang et al PLoS One, 2008

10 Signaling effects: Other factors: age, inflammation amyloid p75 receptors Ca 2+ /Ox mito membrane effects Rho/GDI Death adaptors Survival adaptors Rho A PKA calpain MLK PI3K p-cofilin p-creb cdk5 p38 GSK3β JNK AKT p-tau / mf-tau / tau-o / ml-tau p-fyn Synaptic dysfunction Spine loss Neurite degeneration p-nr2b

11 Signaling effects: Other factors: age, inflammation amyloid p75 receptors Ca 2+ /Ox mito membrane effects Rho/GDI Death adaptors Survival adaptors Rho A PKA calpain MLK PI3K p-cofilin p-creb cdk5 p38 GSK3β JNK AKT p-tau / mf-tau / tau-o / ml-tau p-fyn Synaptic dysfunction Spine loss Neurite degeneration p-nr2b Yang et al PLoS One 2008 Nguyen et al, JAD 2014 Yang et al, SNS 2014

12 p75 NTR ligands block Aβ-induced p-tau / AT8 epitope Aβ AT8 p-tau Ser202 tau p-tau 202 / tau *** *** *** *** E17 div 21 hippocampal neurons Aβ 1-42 (5μM) Modified from Yang et al PLoS One, 2008

13 Inhibition of Aβ-induced tau mislocalization E17 DIV 21 hippocampal neurons CM Aβ Aβ + C31 (100 nm) MAP2 (dendrites) Tau (axons) ** yellow µm / 100 µm ** FYN-NR2B activation? CM Aβ Aβ + C31 (100 nm) Yang, Longo SNS 2014

14 Inhibition of Aβ-induced FYN and NR2B activation 21 DIV HC neurons p-fyn: CM Aβ Aβ + LM11A-31 p-fyn intensity / neuron (% control) Yang, Longo SNS 2014

15 Inhibition of Aβ-induced FYN and NR2B activation 21 DIV HC neurons p-fyn: CM Aβ Aβ + LM11A-31 p-fyn intensity / neuron (% control) p-nr2b: CM Aβ Aβ + LM11A-31 p-nr2b intensity / neuron (% control) ** ** Yang, Longo SNS 2014

16 Inhibition of Aβ-induced FYN and NR2B activation 21 DIV HC neurons p-fyn: CM Aβ Aβ + LM11A-31 p-fyn intensity / neuron (% control) p-nr2b: CM Aβ Aβ + LM11A-31 p-nr2b intensity / neuron (% control) ** ** LTP/behavior? Yang, Longo SNS 2014

17 In vivo Studies Orally bioavailable CNS Water soluble, stable Brain/plasma > 1 Brain T1/2 ~ 1 hr FDA limit dose 2000 mg/kg non-toxic AMES / herg / CYP each clear ADMET favorable CNS target engagement: p75 cleavage

18 Reduced tau phosphorylation (AT8) APP L/S mice; 50 mg/kg po qd X 3 mo Mo: p-tau Ser 202 (AT8) ctx WT veh WT L Intraneuronal p-tau Tg veh Tg L WT-V WT-L Tg-V Tg-L Nguyen et al, JAD 2014

19 Reduced tau aberrant folding (MC-1) APP L/S mice; 50 mg/kg po qd X 3 mo Mo: L ctx: Nguyen et al JAD 2014

20 Reduction of cortex ChAT neurite loss APP L/S mice; 50 mg/kg po qd X 3 mo Mo: WT veh WT-L Tg veh Tg-L WT-V WT-L Tg-V Tg-L Nguyen et al JAD 2014

21 Reduced loss of LC noradrenergic projection fibers to prefrontal ctx APP L/S mice; 50 mg/kg po qd X 3 mo Mo: TH IHC WT-V WT-L Tg-V Tg-L Nguyen, Longo

22 p75 NTR ligands: LTP and behavior APP-L/S mice 3 mo rx: fepsp slope (% of baseline) Time (min) Ottavio Arancio Lab, Columbia HC slice preparations wt-veh wt-c31 APP/PS1-veh APP/PS1-C31 NOR CFC Y-maze DMP-MWM Knowles et al Neurobiol Aging 2013 Nguyen et al JAD 2014

23 Late stage reversal of BF neurite degeneration APP L/S mice; 50 mg/kg po qd X 1 mo Mo: baseline degen rx W TgV TgL Simmons et al PLoS One 2014

24 Spines: late stage rx with p75 NTR ligands APP L/S mice; 50 mg/kg po qd X 1 mo Mo: Golgi staining HC pyramidal L WT V T41 V T41 L WT V T41 V T41 L Simmons, Longo

25 Microglial activation? Other factors: age, inflammation amyloid p75 receptors Ca 2+ /Ox mito membrane effects Rho/GDI Death adaptors Survival adaptors Rho A PKA calpain MLK PI3K p-cofilin p-creb cdk5 p38 GSK3β JNK AKT p-tau / mf-tau / tau-o / ml-tau p-fyn Synaptic dysfunction Spine loss Neurite degeneration p-nr2b

26 Reduction of microglial activation APP L/S mice; 50 mg/kg po qd X 3 mo Mo: Aberrantly folded tau MG activation Zilka et al J Neuroinflammation, 2012 WT veh WT 31 L Cortex Hippocampus Tg veh Tg 31 L L L L L CD68 IHC PET imaging? Nguyen et al JAD 2014

27 Aged WT mice: reversal of BFCN atrophy 50 mg/kg qd X 4 mo Mo: ChAT IHC MS+VDB 200 p=0.001 p=0.012 ChAT Cell Area mo 25 mo V 25 mo L V 25L 18 mo Xie, Meeker, Longo UNC-CH

28 Challenge of mouse to human prediction Our strategies: Many AD-relevant mechanisms Many in vivo endpoints: morphology, behavior Multiple AD models: APP-L/S (morphology, behavior, mechanisms) Ts65Dn (morphology, behavior) Tg2576 (morphology) PS1-APP(LTP) Effects in aged wild-type mice Reversal of late-stage effects Translatable biomarkers: PET 5 models

29 Phase 1: LM11A-31-M Safety and Pharmacokinetics Single ascending dose (SAD), 6 cohorts: Young subjects: D1-4 dose ascending Elderly: D4 (fasted and non-fasted) 48 subjects (36 drug / 12 placebo) Multiple ascending dose (MAD 10 days), 2 cohorts: Elderly D5 2x/day Elderly D6 1x/day 20 subjects (16 drug / 4 placebo) No serious Adverse Events (AEs) Total: 68 subjects (52 drug / 16 placebo) LM11A-31-M is safe and well tolerated in the target elderly population PharmatrophiX

30 PET/MRI Imaging TSPO ligand: GE-180 Michelle James & Sam Gambhir, Stanford

31 GE-180 PET: APP-L/S mice; 3 mo rx (start mo) wt-vehicle APP L/S -vehicle wt-c31 APP L/S -C31 10 ctx: %ID/g HC: 0 normalized PET signal Cortex *** * normalized PET signal Hippocampus ** * James et al Longo-Gambhir SNS 2014

32 Next: Phase 2a study in mild AD Exploratory endpoint 6 mo rx Biomarkers: FDG-PET, MRI CSF p-tau/tau, Aβ, choline acetyltransferase activity Clinical measures: ADAS-Cog-14, NPI, Cogstate