Advances in Alzheimer's Disease: New Technologies and New Ethical Issues

1. National Press Foundation Washington, DC May 24, 2011 Advances in Alzheimer's Disease: New Technologies and New Ethical Issues Steven T. DeKosky, MD James Carroll Flippin Professor of Medical ScienceVice President and DeanUniversity of Virginia School of MedicineCharlottesville, VA USA

2. Disclosures Consultant/Advisory Boards : Bristol Myers Squibb, Eisai, Lilly, Merck, Novartis, Pfizer, PsychoGenics Research Grants: • Elan, Forest, Janssen, Novartis Special acknowledgements: Stephen Post, Stony Brook University Robert Green, Boston University

3. Outline of Discussion • From rare disease to coming epidemic • Technology and research breakthroughs • The value of basic research • Examples in Alzheimer’s Disease • Ethical issues arising • Advances in technology and their effects on AD research, therapies, and caregiving

4. Case Study 46 year old married female • General good health; on no medications • No major medical problems • Sub-acute onset of pathological jealousy • Onset of dysnomia (calls a pitcher a ‘milk pourer’) • Difficulties with short term memory • General medical examination normal • Neurological examination normal except for mental status • Progressive cognitive decline, death 4 years later

5. “I have lost myself.” Alzheimer’s original patient: Auguste D.

6. Alzheimer’s Disease Memory loss Language disturbances Visuospatial deficits “Frontal-Dysexecutive”: Impaired judgment, motivation, insight, decreased social cognition Neuropsychiatric symptoms: depression, anxiety, sleep disturbance psychosis Alzheimer’s original patient: Auguste D. The anatomical/circuitry correlates of these behaviors are now largely identified

7. Alois Alzheimer Germany, 1907: single case report rare, unusual disease of middle-aged “pre-senile dementia” Martin Roth and colleagues Newcastle, 1964: community survey fairly common disease of elderly “senile dementia” From Clinic to Community:characterizing the clinical pictureof AD Majority of cases of dementia in late life are AD,with many cases showing additional co-morbidities

8. 1976 Katzman editorial: an alarm is sounded • Katzman, R. The prevalence and malignancy of Alzheimer disease. A major killer. Archives of Neurology, 1976 • Predicted a massive increase in the number of cases of Alzheimer’s Disease in the 21stcentury • No clear difference between presenile and senile onset with respect to symptoms or pathology • Stimulated research in aging and AD brain

9. Prevalence of Mild, Moderate/Severe and Total Cases of AD: 2000-2050 12 Mild Mod/Severe 10 8 Number of Cases (in millions) 6 4 2 0 2000 2010 2020 2030 2040 2050 Assume no new therapy Sloane, et al., Ann. Rev. Public Health 2002. 23:213–31

10. Increasing Global Burden of AD:Cultures differ in their dealing with dementia

11. Technology & Alzheimer Breakthroughs • “Heavy metal” (silver) stains and Alzheimer • Radioassay for ChAT (Fonnum) in 1975 • Protein purification techniques • Gene sequencing • Neuroimaging: CT, MRI, PET • Computing power to calculate…and to share!

12. Categories of Ethics Questions in AD (and other late life dementias) • Moral, cultural and socio-political issues • Respect and autonomy • balance of responsibility to individual vs. society, e.g., driving privileges • End of Life Care • Comfort, feeding, withholding nutrition or water • Diagnosis and Truthtelling • The Role of Biomarkers • Confirmation of Diagnosis, EarlierDiagnosis, RiskAssessment in Normals

13. Moral, Cultural, and Socio-Political Issues • Affirmation of and respect for people with AD and other disorders involving loss of self (e.g., “deeply forgetful”) • Example, South Korea efforts to honor people with dementia • Justice and protection • Whose responsibility are the Deeply Forgetful? Family? Society? Government? • South Korea’s view… all of them • Respite for family caregivers • Increased morbidity and mortality • Ethicists: Cultivate a ‘culture of acceptance’ • The glass is half full (celebrate what is still available to others, not continue to mourn for what is lost)

14. Biomarkers • Diagnostic Confirmation • Increased Accuracy in MCI • Risk Assessment in Asymptomatic People • What are they? How should they be used? Research or general availability?

15. Alzheimer’s Disease: Course, Prevention, Treatment Strategies Normal Pre-symptomatic AD Mild Cognitive Impairment AD Clinical State Disease Progression

16. Linking Clinical Symptoms With Degree of Pathology Primary Prevention Secondary Prevention/ Early Tx Treatment Intervention Normal Pre-symptomatic AD Mild Cognitive Impairment AD Clinical State Brain Pathologic State Early Brain Changes No Symptoms AD Brain Changes Mild Symptoms Mild, Moderate, or Severe Impairment No Disease No Symptoms Disease Progression

17. Major Pathological Changes in AD • Brain shrinkage (atrophy) • Neuritic Plaques • altered metabolism of APP • Deposition of beta amyloid • Neurofibrillary Tangles • Cytoskeletal pathology [girders and trusses] • Altered metabolism of tau protein • Neuronal deathin specific brain regions (why some regions and not others?) • Specific Neurotransmitter deficits(especially ACh, serotonin, norepinephrine, glutamate)

18. Inflammatory surround Compacted amyloid core NeuroFibrillary Tangles & Neuritic Plaques Neurofibrillary tangles The ‘inflammatory surround’ consists of distorted and degenerating synaptic processes, activated microglia, and astrocytic processes

19. Tau (Microtubule Associated Protein MAP2):Axonal Dissolution and Dysfunction in AD

20. Tangle (NFT) & Plaque (NP) Distribution In AD at Autopsy: The Static View of the 1980s-90s NFT NP S. Arnold, Cortex, 1991

21. Stages A35 A28 A34 A38 A20 A21 A22, 10, 39 A44 A4 A18 A17 S0 Brodmann areas n=30 n=3 trans- entorhinal S3 S1 Distribution of PHF-Tau + entorhinal n=4 S2 S4 n=16 + hippocampus S3 + anterior temporal ctx n=10 S4 S6 n=12 + inferior temporal S5 + mid temporal n=11 S6 S8 + anterior frontal, superior temporal, inferior parietal S7 n=15 S8 + Broca area n=5 S9c S9a n=6 + motor cortex S9b,c n=13 + occipital areas S10 n=27 All cortical areas affected. Delacourte A, et al. Neurology. 1999;52:1158-1165. Biochemical pathway of neurofibrillary degeneration

22. Types of Biomarkers • Genetic • "Risk alleles" e.g. ApoLiprotein E; APOE • Biochemical • CSF Beta amyloid, tau, phosph-tau • Neuroimaging • MRI, FDG-PET, amyloid imaging

23. APOE and Alzheimer’s Disease ALLELE FREQUENCY: • normal population: in AD: • E2 7% 7% • E3 79% 40-50% • E4 14% 40-50% Potential mechanisms: Impaired removal of beta amyloid Diminished neural regenerationAllele frequency twice as high in Africans & African Americans as in Caucasians(~40% v 22%)

24. Genetic Biomarkers • APOE is the major risk gene in AD • REVEAL study, now 10 years on, has tracked individuals views and reactions to have genetic status “revealed.” • Results benign thus far • No other genes of near-equal power are likely to be discovered

25. REVEAL Conclusions • Disclosure of APOE does not seem harmful • may actually reduce anxiety for some who find they are e4- • Persons alter their LTC insurance purchasing learning their APOE genotype • If widespread would have insurance industry implications • APOE4+ carriers • more likely to make changes (vitamins, exercise) even knowing such changes are not proven • Also more likely to purchase unregulated neutraceuticals • The impact is less than expected • people come into the study with a baseline perception of their own risk • seem to have a psychological inertia

26. Structural and Biochemical Biomarkers • Biochemical: CSF Beta amyloid, tau, phosph-tau • Diagnostic as well as predictivevalue • Neuroimaging: MRI, FDG-PET, amyloid imaging • Used for diagnosticconfirmation in a symptomatic person, for earlierdefinitivediagnosisin mildoruncertainsymptoms (e.g., MCI), and for detection of AD pathology in asymptomaticindividuals.

27. Evolution of Neuroimaging • Computed Tomography • MRI • Volumetric MRI • FDG Glucose PET • Co-registration of MRI • Functional MRI • Amyloid Imaging 1970s 1980s 1990s 2000s

29. Evolution of Volume Mapping 39 Enhancing ability to assess variability of structural change AND response tomedications. Helmuth L. Science. 2002;297:1260-1262. www.loni.ucla.edu/~thompson/AD_4D/dynamic.html.

30. Ethics Issues With Biomarkers • Diagnostic information • We can ascertain with high probability whether AD pathology is present in the brain • How much to tell research participants about unvalidated research results?

31. Best markers across a broad range are MRI and FDG-PET CSF Aβ42 Amyloid imaging MRI hipp CSF tau FDG-PET Fxn Cog

33. Biomarkers for Earlier Diagnosis “They stipulate that there must also be at least one or more abnormal biomarkers among structural neuroimaging with MRI, molecular neuroimaging with PET, and cerebrospinal fluid analysis of amyloid β or tau proteins. “ Lancet Neurol 2007; 6: 734–46

34. CSF in Alzheimer’s Disease: Low Aβ and High Tau Concentration (pg/mL) Aβ Tau Sunderland T, et al. JAMA. 2003;289:2094-2103.

35. CSF in MCI has elevated tau, decreased β-amyloid Hansson et al.,2006

36. Imaging Amyloid in vivo in Humans • Amyloid Cascade Hypothesis: • Amyloid deposition begins years before clinical symptoms • Ability to image brain amyloid will impact: • Diagnosis (sensitivity and specificity TBD) • Prognosis (different patterns of progression?) • Monitoring anti-amyloid therapeutic interventions • Efficiency of drug development • Current ligands, more in development: • PiB (GE), AV-45 (AVID/Lilly), Bayer • PiB: Now in use in over 60 centers around the world • F18-PiB in development at both GE and Pittsburgh • Just as accurate as C11-PiB

37. PIB PET in AD and Control

38. Amyloid Imaging Agents Florbetapir (Amyvid) Florbetaben (Bayer) AV45 (AVID/Lilly)

40. C-8 C-2 MCI-2 MCI-10 MCI-4 AD-2 PIB Retention Distribution Volume Ratio (DVR) 1.06 1.64 1.04 1.62 2.59 2.48 Frontal DVR

41. Prediction of Outcome Utilizing PiB Imaging in MCI: PiB+ Cases Develop AD; PiB- Cases Do Not 23/26 patients have had follow-up ADRC evaluations Mean f/u: 24.0 months (6-57 months) 13 PiB positive (Mean f/u: 23.6 months) 10 PiB negative (Mean f/u: 24.5 months) Wolk, et al., 2009

42. Prevalence of Plaques Precede DAT

43. 20 22 23 49 49 51 56 57 58 58 59 59 59 60 60 60 61 61 62 64 64 66 71 72 72 74 75 75 75 76 77 77 77 79 80 81 83 83 84 85 86 86 72 73 73 79 79 81 84 85 86 Mean Cortical PIB Binding in Nondemented Controls and AD (N=41) 1.200 Controls AD 1.000 0.800 0.600 scBP 0.400 0.200 0.000 -0.200 Subject AGE Mintun et al, 2006, Neurology

44. Longitudinal Change in PiB Retention in a Questionably Positive Control over Two Years 2 yrs

45. PiB Binding (amyloid plaque density)in Cognitively Normal Elderly and AD Aizenstein et al., Arch. Neurol. 2008; 65: 1509-1517

46. Heterogeneity of Amyloid Binding in Asymptomatic Normal Elderly Courtesy of Reisa Sperling, Harvard Univ.

47. How will disease-modifying medications affect the field? • Immediate pressure to identify subjects as early as possible • Amyloid scans beginning at age 50, repeated every 5 years, as for colon cancer • Public Health Message: “At 50, get evaluated head to tail! Have your colonoscopy and your PiB Scan.”

48. Operational Research Criteria for Preclinical AD • Not intended as clinical diagnostic criteria • Prognostic utility of these biomarkers in individual subjects remains unclear • Not all individuals with neuroimaging evidence of AD changes will develop clinical symptoms during life • 30% of non-demented 80+ year olds have evidence of AD in the brain at autopsy

49. Overview of Phase III AD Trials • Negative Phase III: • Xaliproden (5HT1A agonist with neurotrophic effects in vitro) • Tramiprosate (GAG anti-aggregant) • Tarenflurbil (R flurbiprofen, gamma secretase modulator) • Rosiglitazone (Peroxisome proliferators activated receptor PPAR-ү) • Leuprolide (LHRH endocrine) • Dimebon (5HT6 antagonist, H1 antagonist + mitochondrial transition pore) • Semagacestat (gamma secretase inhibitor) • Phase III in progress • Bapineuzumab (passive immunotherapy; monoclonal Ab N-terminal ) • Solanezumab (passive immunotherapy; monoclonal mid domain Ab) • IVIG (passive immunotherapy; polyclonal pooled Abs) • Dimebon (5HT6 antagonist, H1 antagonist + mitochondrial transition pore) • Tau Rx (methylene blue, anti tau aggregant)

50. Phase II Bapineuzemab Study “Due to varying doses and a lack of statistical precision, this Class II ascending dose trial provides insufficient evidence to support or refute a benefit of bapineuzumab.” Salloway et al., 2009