Alzheimer's Disease
Conditions
Interventions
The study consists of two active dose arms of MK-8931 (12 mg and 40 mg), and
placebo. One group will receive a once daily 12 mg tablet with product MK8931.
One group will receive a once daily 40 mg
Sponsors
Merck Sharp & Dohme (MSD)
Eligibility
Age
18 Years to 99 Years
Inclusion criteria
Inclusion criteria: Each subject must:;Added for the extension study: Male/Female subjects who completed the initial 104-week trial.;For the main study: * Be * 50 and * 85 years of age at the Screening Visit.;* Meet the following criteria for a diagnosis of prodromal AD:;o Each subject must report a history of subjective memory decline with gradual onset and slow progression for at least one year before Screening, that is either corroborated by an informant who knows the subject well or is documented in medical records.;o Each subject must have objective impairment in episodic memory at Screening that is *1.0 SD below the appropriate population mean as measured by the screening memory test [Repeatable Battery for the Assessment of Neuropsychological Status (RBANS)]. An RBANS delayed memory index score of *85 is required for entry. (Note: the proportion of subjects with RBANS delayed memory index scores ranging from 79 to 85 (approximately 1.5 to 1.0 SD below the appropriate population mean), inclusive, will not exceed 15-30% of the total number randomized).;o Each subject must have general cognitive function and activities of daily living sufficiently intact, based on clinical assessment, so as not to meet criteria for mild AD dementia (based on DSM-IV-TR and NINCDS-ADRDA criteria).;o Each subject must have a positive amyloid imaging PET scan using [18F]flutametamol at Screening or positive CSF tau:A*42 ratio at Screening (see Trial Manuals for details). PET is the primary inclusion tool for the trial. Subjects who fail to meet inclusion criteria based on PET but qualify based on CSF will be enrolled in a separate CSF subgroup of the trial. (Refer to Protocol Section 7.1.3.4 for direction regarding initiation of CSF collection in the trial.);* Have an MMSE score * 24 at Screening.;* Be able to read at a 6th grade level or equivalent, as determined by the investigator, and must have a history of academic achievement and/or employment sufficient to exclude mental retardation.;* If receiving an acetylcholinesterase inhibitor, memantine, medical food/supplement, and/or herbal medications for AD, be on a stable dose for at least the three months before Screening, and the subject must be willing to remain on the same dose for the duration of the trial. The treatment and dose that the subject is receiving at Screening must not be changed during the trial unless medically necessary. Additional treatments [including herbal medications] for AD that are not specified in the protocol must not be initiated during the trial. The subject and trial partner must agree that they do not plan to discontinue treatment or initiate additional AD treatments during the trial unless medically necessary. (See Protocol Section 5.5.2 for additional details regarding use of other AD therapy.);* Have a reliable and competent trial partner/informant who must have a close relationship with the subject, have face to face contact at least three days a week for a minimum of six waking hours a week, be willing to accompany the subject to all trial visits, and be willing to monitor compliance of the administration of the trial medication. The trial partner/informant should understand the nature of the trial and adhere to trial requirements (e.g., dose, visit schedules, receive phone calls, and evaluations).;* Have results of clinical laboratory tests (complete blood count [CBC], blood chemistries, thyroid stimulating hormone [TSH], and urinalysis) within normal limits or clinically
Exclusion criteria
Exclusion criteria: The subject must be excluded from participating in the trial if the subject:;Added for the extension study: 1. Based on results from the EOT Visit (Visit 12) in the initial 104-week trial has results of clinical laboratory tests (complete blood count [CBC], blood chemi stries, and urinalysis) that are clinically unacceptable to the investigator. 2. Based on the results from the EOT Visit (Visit 12) has results of a physical examination, and vital signs that are clinically unacceptable to the investigator.;For the main study: * Has a Rosen modified Hachinski Ischemia Score > 4 at Screening (i.e., evidence of vascular dementia).;* Has a known history of stroke or evidence from screening MRI scan that is clinically important in the investigator's opinion.;* Meets the criteria for a diagnosis of dementia, including probable or possible AD, based on DSM IV TR or NINCDS ADRDA criteria at Screening or Baseline.;* Has evidence of a clinically relevant neurological disorder other than the disease being studied (i.e., prodromal AD) at Screening, including but not limited to: vascular dementia, parkinsonism, frontotemporal dementia, Huntington's disease, amyotrophic lateral sclerosis, multiple sclerosis, progressive supranuclear palsy, neurosyphilis, dementia with Lewy bodies, other types of dementia, mental retardation, hypoxic cerebral damage, cognitive impairment due to other disorders, or head trauma with loss of consciousness that led to persistent cognitive deficits.;* Has evidence of a clinically relevant or unstable psychiatric disorder, based on DSM IV TR criteria, including schizophrenia or other psychotic disorder, bipolar disorder, major depression, or delirium. Major depression in remission is not exclusionary.;* Has evidence of a current episode of major depression based on investigator's judgment. A score on the 15-item Geriatric Depression Scale (GDS) of 5 or more requires an assessment by an appropriate health care professional to evaluate for the presence of major depression. Subjects with a score of 5 or more who are not diagnosed with major depression following such an assessment may be included in the trial.;* Has an MRI scan obtained at Screening that shows evidence of a neurological disorder other than prodromal AD or > 4 cerebral microhemorrhages (regardless of their anatomical location or diagnostic characterization as "possible" or "definite"), a single area of superficial siderosis, evidence of a prior macrohemorrhage, > 3 lacunar infarcts over 10 mm each, any cortical infarct over 10 mm, or any other clinically significant finding (e.g., any lesion that may account for their cognitive impairment, including but not limited to brain tumor, severe white matter disease with a rating of 3 on the age-related white matter changes (ARWMC) scale, arteriovenous malformation, cavernous hemangioma, or any infarct in a strategic subcortical location).;* Has a history of hepatitis or liver disease that, in the opinion of the investigator, has been active within the six months prior Screening.;* Has a recent or ongoing, uncontrolled, clinically significant medical condition within three months of the Screening Visit (such as, but not limited to, diabetes, hypertension, thyroid or endocrine disease, congestive heart failure, angina, cardiac or gastrointestinal disease, dialysis, or abnormal renal function with estimated creatinine clearance < 30 mL/min) other than the condition
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| The primary efficacy endpoint is the change from Baseline in the CDR-SB score at Week 104. | — |
Secondary
| Measure | Time frame |
|---|---|
| the time to progression to probable AD dementia the mean difference between the last (Week 104) and first (Week 13) postdose timepoint in CDR-SB the change from Baseline at Week 104 in the CCS-3D the change from Baseline at Week 104 in total hippocampal volume the change from Baseline at Week 104 in CSF total tau the change from Baseline at Week 104 in composite cortical amyloid standard uptake value ratio assessed with amyloid tracer [18F]Flutemetamol using PET imaging the change from Baseline at Week 104 in ADCS-ADLMCI score | — |
Countries
Netherlands
Outcome results
None listed