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Efficacy and Safety Trial of Verubecestat (MK-8931) in Participants With Prodromal Alzheimer's Disease (MK-8931-019) (APECS)

Primary Purpose

Amnestic Mild Cognitive Impairment, Alzheimer's Disease, Prodromal Alzheimer's Disease

Status
Terminated
Phase
Phase 3
Locations
Study Type
Interventional
Intervention
Verubecestat 12 mg (Parts 1 and 2)
Verubecestat 40 mg (Parts 1 and 2)
Placebo (Part 1)
Sponsored by
Merck Sharp & Dohme LLC
About
Eligibility
Locations
Arms
Outcomes
Full info

About this trial

This is an interventional treatment trial for Amnestic Mild Cognitive Impairment

Eligibility Criteria

50 Years - 85 Years (Adult, Older Adult)All SexesDoes not accept healthy volunteers

Inclusion Criteria:

  1. Diagnosis of prodromal AD, including the following:

    1. History of subjective memory decline with gradual onset and slow progression for at least one year corroborated by an informant,
    2. Objective impairment in episodic memory by memory test performed at Screening,
    3. Does not meet criteria for dementia, AND
    4. Positive Screening amyloid imaging PET scan using [18F]flutametamol tracer or positive Screening CSF tau:amyloid-β42 (Aβ42) ratio (Participants with a prior positive amyloid imaging PET scan or a Screening PET scan with florbetaben or florbetapir may be enrolled without a Screening flutemetamol scan with Sponsor approval)
  2. Able to read at a 6th grade level or equivalent
  3. If participant is receiving an acetylcholinesterase inhibitor or memantine, the dose must have been stable for at least three months before Screening
  4. Must have a reliable and competent trial partner/informant who has a close relationship with the participant and is willing to accompany the participant to all required trial visits, and to monitor compliance of the administration of the trial medication

Inclusion Criteria for Extension Period (Part 2):

  1. Tolerated study drug and completed the initial 104-week period of the trial (Part 1)
  2. Participant must have a reliable and competent trial partner who must have a close relationship with the subject

Exclusion Criteria:

  1. History of stroke
  2. Evidence of a clinically relevant neurological disorder other than the disease being studied (i.e., prodromal AD)
  3. History of seizures or epilepsy within the last 5 years
  4. Evidence of a clinically relevant or unstable psychiatric disorder, excluding major depression in remission
  5. Participant is at imminent risk of self-harm or of harm to others
  6. History of alcoholism or drug dependency/abuse within the last 5 years before Screening
  7. Participant does not have a magnetic resonance imaging (MRI) scan obtained within 12 months of Screening and is unwilling or not eligible to undergo an MRI scan at the Screening Visit. With Sponsor approval, a head computed tomography (CT) scan may be substituted for MRI scan to evaluate eligibility
  8. History of hepatitis or liver disease that has been active within the 6 months prior to Screening
  9. Recent or ongoing, uncontrolled, clinically significant medical condition within 3 months of Screening
  10. History of malignancy occurring within the 5 years before Screening, except for adequately treated basal cell or squamous cell skin cancer, in situ cervical cancer, or localized prostate carcinoma
  11. Clinically significant vitamin B12 or folate deficiency in the 6 months before Screening
  12. Use of any investigational drugs or participation in clinical trials within the 30 days before Screening
  13. History of a hypersensitivity reaction to more than three drugs
  14. Has human immunodeficiency virus (HIV) by medical history
  15. Participant is unwilling or has a contraindication to undergo PET scanning including but not limited to claustrophobia, excessive weight or girth
  16. History or current evidence of long QT syndrome, corrected QT (QTc) interval ≥470 milliseconds (for male participants) or ≥480 milliseconds (for female participants), or torsades de pointes
  17. Close family member (including the trial partner, spouse or children) who is among the personnel of the investigational or sponsor staff directly involved with this trial

Exclusion Criteria for Extension Period (Part 2):

  1. Participant is at imminent risk of self-harm or of harm to others
  2. Has developed a recent or ongoing, uncontrolled, clinically significant medical or psychiatric condition
  3. Results of safety assessments (e.g., laboratory tests) performed in participant at end of Part 1 that are clinically unacceptable to the Investigator
  4. Has developed a form of dementia that is not AD
  5. Has progressed to dementia due to AD per investigator diagnosis in the initial 104-week study (Part 1).

Exclusion Criteria for NFT PET Substudy (Part 2):

1. Had one or two PET scans with MK-6240 in the initial 104-week study.

Sites / Locations

    Arms of the Study

    Arm 1

    Arm 2

    Arm 3

    Arm Type

    Experimental

    Experimental

    Placebo Comparator

    Arm Label

    Arm A. Verubecestat 12 mg (Part 1); 12 mg (Part 2)

    Arm B. Verubecestat 40 mg (Part 1); 40 mg (Part 2)

    Arm C. Placebo (Part 1); Verubecestat 40 mg (Part 2)

    Arm Description

    [Part 1] Verubecestat 12 mg once daily for 104 weeks in Part 1 (Base Study). [Part 2] Participants completing Part 1 and continuing to Part 2 (Extension Study) receive Verubecestat 12 mg once daily for an additional 260 weeks.

    [Part 1] Verubecestat 40 mg once daily for 104 weeks in Part 1 (Base Study). [Part 2] Participants completing Part 1 and continuing to Part 2 (Extension Study) receive Verubecestat 40 mg once daily for an additional 260 weeks.

    [Part 1] Placebo once daily for 104 weeks in Part 1 (Base Study). [Part 2] Participants completing Part 1 and continuing to Part 2 (Extension Study) receive Verubecestat 40 mg once daily for an additional 260 weeks.

    Outcomes

    Primary Outcome Measures

    Part 1 (Base Study). Least Squares Mean (LSM) Change From Baseline in Clinical Dementia Rating Sum of Boxes (CDR-SB) Score at Week 104
    LSM change from baseline at week 104 was assessed for CDR-SB score, a clinical rating of global cognitive function, comprised of 6 domains: memory; orientation; judgment and problem solving; community affairs; home and hobbies; and personal care. For each domain, the degree of impairment is assessed by a semi-structured interview of the participant as well as the participant's caregiver. For each domain, potential scores range from 0 (no impairment) to 3 (severe impairment). Individual domain scores are summed to a total CDR-SB score (range: 0-18). Higher scores indicate more severe cognitive impairment. Further, increases in cognitive impairment would be reflected by increases in CDR-SB score.
    Part 2 (Extension Study). Mean Change From Baseline in Clinical Dementia Rating Sum of Boxes (CDR-SB) Score at Week 130
    Mean change from baseline at week 130 was assessed for CDR-SB score, a clinical rating of global cognitive function, comprised of 6 domains: memory; orientation; judgment and problem solving; community affairs; home and hobbies; and personal care. For each domain, the degree of impairment is assessed by a semi-structured interview of the participant as well as the participant's caregiver. For each domain, potential scores range from 0 (no impairment) to 3 (severe impairment). Individual domain scores are summed to a total CDR-SB score (range: 0-18). Higher scores indicate more severe cognitive impairment. Further, increases in cognitive impairment would be reflected by increases in CDR-SB score. Per protocol, baseline refers to the baseline measurement obtained in Part 1.
    Part 1 (Base Study). Percentage of Participants Who Experienced ≥1 Adverse Event (AE)
    The percentage of participants experiencing an AE in Part 1 was assessed. An AE is defined as any untoward medical occurrence in a patient or clinical investigation subject administered a pharmaceutical product and which does not necessarily have to have a causal relationship with this treatment. An AE can therefore be any unfavorable and unintended sign, symptom, or disease temporally associated with the use of a medicinal product, whether or not considered related to this medicinal product. Any worsening of a preexisting condition that is temporally associated with the use of the Sponsor's product is also an AE.
    Part 1 (Base Study). Percentage of Participants Who Discontinued From Study Drug Due to an Adverse Event (AE)
    The percentage of participants who discontinued from study drug due to an AE in Part 1 was assessed. An AE is defined as any untoward medical occurrence in a patient or clinical investigation subject administered a pharmaceutical product and which does not necessarily have to have a causal relationship with this treatment. An AE can therefore be any unfavorable and unintended sign, symptom, or disease temporally associated with the use of a medicinal product, whether or not considered related to this medicinal product. Any worsening of a preexisting condition that is temporally associated with the use of the Sponsor's product is also an AE.
    Part 2 (Extension Study). Percentage of Participants Who Experienced ≥1 Adverse Event (AE)
    The percentage of participants experiencing an AE in Part 2 was assessed. An AE is defined as any untoward medical occurrence in a patient or clinical investigation subject administered a pharmaceutical product and which does not necessarily have to have a causal relationship with this treatment. An AE can therefore be any unfavorable and unintended sign, symptom, or disease temporally associated with the use of a medicinal product, whether or not considered related to this medicinal product. Any worsening of a preexisting condition that is temporally associated with the use of the Sponsor's product is also an AE.
    Part 2 (Extension Study). Percentage of Participants Who Discontinued From Study Drug Due to an Adverse Event (AE)
    The percentage of participants who discontinued from study drug due to an AE in Part 2 was assessed. An AE is defined as any untoward medical occurrence in a patient or clinical investigation subject administered a pharmaceutical product and which does not necessarily have to have a causal relationship with this treatment. An AE can therefore be any unfavorable and unintended sign, symptom, or disease temporally associated with the use of a medicinal product, whether or not considered related to this medicinal product. Any worsening of a preexisting condition that is temporally associated with the use of the Sponsor's product is also an AE.

    Secondary Outcome Measures

    Part 1 (Base Study). Event-Rate Per 100 Participant Years for Progression to a Clinical Diagnosis of Probable AD Dementia
    The event-rate per 100 participant-years for progression to a clinical diagnosis of probable AD dementia was calculated. Adjudication of a potential case was triggered if either: 1) in the investigator's own expert judgment, they think the participant may have progressed to dementia and/or 2) the participant's CDR-SB score is ≥2 points higher compared to baseline. Cases of progression to probable AD dementia confirmed by an external adjudication committee were counted as events in the analysis. The event-rate was calculated as the number of events divided by total follow-up time (participant-years) x 100; unit of measure is event-rate / 100 participant-years.
    Part 1 (Base Study). Estimated Least Squares Mean Difference Between the Last (Week 104) and First (Week 13) Post-dose CDR-SB Assessment
    LSM difference between weeks 104 and 13 was estimated for CDR-SB score, a clinical rating of global cognitive function, comprised of 6 domains: memory; orientation; judgment / problem solving; community affairs; home / hobbies; and personal care. For each domain, degree of impairment is scored by a semi-structured interview of the participant and the participant's caregiver (domain score range: 0 [no impairment] to 3 [severe impairment]). Domain scores sum to a total CDR-SB score (range: 0-18); higher scores indicate more severe cognitive impairment. Further, increased cognitive impairment is reflected by higher CDR-SB scores; larger differences between week 104 and week 13 scores indicates accelerated AD progression.
    Part 1 (Base Study). Least Squares Mean Change From Baseline in the 3-Domain Composite Cognition Score (CCS-3D) at Week 104
    CCS-3D is composed of individual cognitive tests, grouped into 3 domains: 1) episodic memory; 2) executive function; and 3) attention/processing speed. For each cognitive test, a z-score (Z) is calculated at each time point [Z = (observed value - study population mean at baseline) / study population standard deviation at baseline]. These individual Zs are first combined into domain-specific Zs, and then into a composite Z, (i.e. CCS-3D). Theoretically, 99.9% of CCS-3D will be ± 3; more positive CCS-3D indicate greater cognitive impairment relative to the total study population at baseline. Further, negative changes in CCS-3D over time indicate improved cognition relative to the total study population at baseline.
    Part 1 (Base Study). Least Squares Mean Percent Change From Baseline in Total Hippocampal Volume (THV) at Week 104
    Least squares mean percent change from baseline at week 104 was calculated for THV as measured by volumetric magnetic resonance imaging (vMRI). Negative percent changes from baseline indicate decreases in THV (i.e. increased hippocampal atrophy).
    Part 1 (Base Study). Least Squares Mean Change From Baseline in Composite Cortical Amyloid Standard Uptake Value Ratio (SUVR) Assessed With Amyloid Tracer [18F]Flutemetamol Using Positron Emission Tomography (PET) Imaging at Week 104
    [18F]Flutemetamol PET SUVR measures brain cortical amyloid load. The PET tracer [18F]Flutemetamol was given intravenously (IV). After 90 minutes, participants were scanned for 20 minutes. Using the PET scan images, SUVRs, the ratio of tracer signal in a specific region compared to a reference region (RR; subcortical white matter) are calculated for brain regions of interest (ROIs). SUVRs from a selected set of brain regions are averaged to compute a composite SUVR. Higher composite SUVR values indicate increased amyloid load in selected brain regions, with negative changes in composite cortical SUVR over time indicating decreases in brain amyloid load.
    Part 1 (Base Study). Least Squares Mean Change From Baseline in Alzheimer's Disease Cooperative Study-Activities of Daily Living Inventory (Mild Cognitive Impairment Version) (ADCS-ADL MCI) Score at Week 104
    Least squares mean change from baseline at week 104 was assessed for the ADCS-ADL MCI score. The ADCS-ADL MCI is an 18-item assessment of recent, observed performance of activities of daily living administered to participants' trial partners in an interview format. For the 18 items, scores range from 0 (no independence) to (depending on the item) either 2 (5 items), 3 (9 items), or 4 (4 items), with higher scores indicating greater independence in activity performance. Scores from individual items sum to a total ADCS-ADL score (range: 0-53). Lower scores indicate less independence in activity performance and, as a result, greater AD severity. Further, increases in AD severity over time would be reflected by decreases in ADCS-ADL score.
    Part 1 (Base Study). Mean Percent Change From Baseline in Cerebrospinal Fluid (CSF) Total Tau Concentration at Week 104
    Mean percent change from baseline at week 104 was calculated for Total Tau concentration in CSF, a measure of brain tau pathology. Per protocol, CSF Total Tau concentration was analyzed as part of a substudy in Part 1, with testing occurring only at select trial sites.

    Full Information

    First Posted
    September 25, 2013
    Last Updated
    May 15, 2019
    Sponsor
    Merck Sharp & Dohme LLC
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    1. Study Identification

    Unique Protocol Identification Number
    NCT01953601
    Brief Title
    Efficacy and Safety Trial of Verubecestat (MK-8931) in Participants With Prodromal Alzheimer's Disease (MK-8931-019)
    Acronym
    APECS
    Official Title
    A Phase III, Randomized, Placebo-Controlled, Parallel-Group, Double-Blind Clinical Trial to Study the Efficacy and Safety of MK-8931 (SCH 900931) in Subjects With Amnestic Mild Cognitive Impairment Due to Alzheimer's Disease (Prodromal AD)
    Study Type
    Interventional

    2. Study Status

    Record Verification Date
    May 2019
    Overall Recruitment Status
    Terminated
    Study Start Date
    November 5, 2013 (Actual)
    Primary Completion Date
    April 17, 2018 (Actual)
    Study Completion Date
    April 17, 2018 (Actual)

    3. Sponsor/Collaborators

    Responsible Party, by Official Title
    Sponsor
    Name of the Sponsor
    Merck Sharp & Dohme LLC

    4. Oversight

    Data Monitoring Committee
    Yes

    5. Study Description

    Brief Summary
    This study consists of two parts, Part 1 and Part 2. Part 1 assesses the efficacy and safety of verubecestat (MK-8931) compared with placebo administered for 104 weeks in the treatment of amnestic mild cognitive impairment (aMCI) due to Alzheimer's Disease (AD), also known as prodromal AD. Participants are randomized to receive placebo, or 12 mg or 40 mg verubecestat, once daily. The primary study hypothesis for Part 1 is that ≥1 verubecestat dose is superior to placebo with respect to the change from baseline in the Clinical Dementia Rating scale-Sum of Boxes (CDR-SB) score at 104 weeks. Participants completing Part 1 may choose to participate in Part 2, which is a long term double-blind extension to assess efficacy and safety of verubecestat administered for up to an additional 260 weeks. In Part 2, all participants receive either 12 mg or 40 mg verubecestat, once daily.
    Detailed Description
    As a result of protocol amendment, Study Part 2 will contain a Positron Emission Tomography (PET) imaging substudy to assess regional neurofibrillary tangle (NFT) expression.

    6. Conditions and Keywords

    Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
    Amnestic Mild Cognitive Impairment, Alzheimer's Disease, Prodromal Alzheimer's Disease

    7. Study Design

    Primary Purpose
    Treatment
    Study Phase
    Phase 3
    Interventional Study Model
    Parallel Assignment
    Masking
    ParticipantInvestigatorOutcomes Assessor
    Allocation
    Randomized
    Enrollment
    1454 (Actual)

    8. Arms, Groups, and Interventions

    Arm Title
    Arm A. Verubecestat 12 mg (Part 1); 12 mg (Part 2)
    Arm Type
    Experimental
    Arm Description
    [Part 1] Verubecestat 12 mg once daily for 104 weeks in Part 1 (Base Study). [Part 2] Participants completing Part 1 and continuing to Part 2 (Extension Study) receive Verubecestat 12 mg once daily for an additional 260 weeks.
    Arm Title
    Arm B. Verubecestat 40 mg (Part 1); 40 mg (Part 2)
    Arm Type
    Experimental
    Arm Description
    [Part 1] Verubecestat 40 mg once daily for 104 weeks in Part 1 (Base Study). [Part 2] Participants completing Part 1 and continuing to Part 2 (Extension Study) receive Verubecestat 40 mg once daily for an additional 260 weeks.
    Arm Title
    Arm C. Placebo (Part 1); Verubecestat 40 mg (Part 2)
    Arm Type
    Placebo Comparator
    Arm Description
    [Part 1] Placebo once daily for 104 weeks in Part 1 (Base Study). [Part 2] Participants completing Part 1 and continuing to Part 2 (Extension Study) receive Verubecestat 40 mg once daily for an additional 260 weeks.
    Intervention Type
    Drug
    Intervention Name(s)
    Verubecestat 12 mg (Parts 1 and 2)
    Other Intervention Name(s)
    MK-8931
    Intervention Description
    Verubecestat 12 mg oral tablet, given once daily.
    Intervention Type
    Drug
    Intervention Name(s)
    Verubecestat 40 mg (Parts 1 and 2)
    Other Intervention Name(s)
    MK-8931
    Intervention Description
    Verubecestat 40 mg oral tablet, given once daily. Verubecestat 40 mg given to participants in Arm C continuing to study Part 2.
    Intervention Type
    Other
    Intervention Name(s)
    Placebo (Part 1)
    Intervention Description
    Placebo matching verubecestat, given once daily as an oral tablet.
    Primary Outcome Measure Information:
    Title
    Part 1 (Base Study). Least Squares Mean (LSM) Change From Baseline in Clinical Dementia Rating Sum of Boxes (CDR-SB) Score at Week 104
    Description
    LSM change from baseline at week 104 was assessed for CDR-SB score, a clinical rating of global cognitive function, comprised of 6 domains: memory; orientation; judgment and problem solving; community affairs; home and hobbies; and personal care. For each domain, the degree of impairment is assessed by a semi-structured interview of the participant as well as the participant's caregiver. For each domain, potential scores range from 0 (no impairment) to 3 (severe impairment). Individual domain scores are summed to a total CDR-SB score (range: 0-18). Higher scores indicate more severe cognitive impairment. Further, increases in cognitive impairment would be reflected by increases in CDR-SB score.
    Time Frame
    Baseline and Week 104 in Part 1
    Title
    Part 2 (Extension Study). Mean Change From Baseline in Clinical Dementia Rating Sum of Boxes (CDR-SB) Score at Week 130
    Description
    Mean change from baseline at week 130 was assessed for CDR-SB score, a clinical rating of global cognitive function, comprised of 6 domains: memory; orientation; judgment and problem solving; community affairs; home and hobbies; and personal care. For each domain, the degree of impairment is assessed by a semi-structured interview of the participant as well as the participant's caregiver. For each domain, potential scores range from 0 (no impairment) to 3 (severe impairment). Individual domain scores are summed to a total CDR-SB score (range: 0-18). Higher scores indicate more severe cognitive impairment. Further, increases in cognitive impairment would be reflected by increases in CDR-SB score. Per protocol, baseline refers to the baseline measurement obtained in Part 1.
    Time Frame
    Baseline and Week 130 (i.e., Week 26 of Part 2)
    Title
    Part 1 (Base Study). Percentage of Participants Who Experienced ≥1 Adverse Event (AE)
    Description
    The percentage of participants experiencing an AE in Part 1 was assessed. An AE is defined as any untoward medical occurrence in a patient or clinical investigation subject administered a pharmaceutical product and which does not necessarily have to have a causal relationship with this treatment. An AE can therefore be any unfavorable and unintended sign, symptom, or disease temporally associated with the use of a medicinal product, whether or not considered related to this medicinal product. Any worsening of a preexisting condition that is temporally associated with the use of the Sponsor's product is also an AE.
    Time Frame
    Up to Week 106 (up to 2 weeks following cessation of study treatment in Part 1)
    Title
    Part 1 (Base Study). Percentage of Participants Who Discontinued From Study Drug Due to an Adverse Event (AE)
    Description
    The percentage of participants who discontinued from study drug due to an AE in Part 1 was assessed. An AE is defined as any untoward medical occurrence in a patient or clinical investigation subject administered a pharmaceutical product and which does not necessarily have to have a causal relationship with this treatment. An AE can therefore be any unfavorable and unintended sign, symptom, or disease temporally associated with the use of a medicinal product, whether or not considered related to this medicinal product. Any worsening of a preexisting condition that is temporally associated with the use of the Sponsor's product is also an AE.
    Time Frame
    Up to Week 104 in Part 1
    Title
    Part 2 (Extension Study). Percentage of Participants Who Experienced ≥1 Adverse Event (AE)
    Description
    The percentage of participants experiencing an AE in Part 2 was assessed. An AE is defined as any untoward medical occurrence in a patient or clinical investigation subject administered a pharmaceutical product and which does not necessarily have to have a causal relationship with this treatment. An AE can therefore be any unfavorable and unintended sign, symptom, or disease temporally associated with the use of a medicinal product, whether or not considered related to this medicinal product. Any worsening of a preexisting condition that is temporally associated with the use of the Sponsor's product is also an AE.
    Time Frame
    From Week 104 (start of treatment in Part 2) up to Week 210 (up to 2 weeks following cessation of study treatment in Part 2)
    Title
    Part 2 (Extension Study). Percentage of Participants Who Discontinued From Study Drug Due to an Adverse Event (AE)
    Description
    The percentage of participants who discontinued from study drug due to an AE in Part 2 was assessed. An AE is defined as any untoward medical occurrence in a patient or clinical investigation subject administered a pharmaceutical product and which does not necessarily have to have a causal relationship with this treatment. An AE can therefore be any unfavorable and unintended sign, symptom, or disease temporally associated with the use of a medicinal product, whether or not considered related to this medicinal product. Any worsening of a preexisting condition that is temporally associated with the use of the Sponsor's product is also an AE.
    Time Frame
    From Week 104 (start of treatment in Part 2) up to Week 208 (i.e., up to Week 104 in Part 2)
    Secondary Outcome Measure Information:
    Title
    Part 1 (Base Study). Event-Rate Per 100 Participant Years for Progression to a Clinical Diagnosis of Probable AD Dementia
    Description
    The event-rate per 100 participant-years for progression to a clinical diagnosis of probable AD dementia was calculated. Adjudication of a potential case was triggered if either: 1) in the investigator's own expert judgment, they think the participant may have progressed to dementia and/or 2) the participant's CDR-SB score is ≥2 points higher compared to baseline. Cases of progression to probable AD dementia confirmed by an external adjudication committee were counted as events in the analysis. The event-rate was calculated as the number of events divided by total follow-up time (participant-years) x 100; unit of measure is event-rate / 100 participant-years.
    Time Frame
    Up to Week 104 in Part 1
    Title
    Part 1 (Base Study). Estimated Least Squares Mean Difference Between the Last (Week 104) and First (Week 13) Post-dose CDR-SB Assessment
    Description
    LSM difference between weeks 104 and 13 was estimated for CDR-SB score, a clinical rating of global cognitive function, comprised of 6 domains: memory; orientation; judgment / problem solving; community affairs; home / hobbies; and personal care. For each domain, degree of impairment is scored by a semi-structured interview of the participant and the participant's caregiver (domain score range: 0 [no impairment] to 3 [severe impairment]). Domain scores sum to a total CDR-SB score (range: 0-18); higher scores indicate more severe cognitive impairment. Further, increased cognitive impairment is reflected by higher CDR-SB scores; larger differences between week 104 and week 13 scores indicates accelerated AD progression.
    Time Frame
    Week 13 and Week 104 in Part 1
    Title
    Part 1 (Base Study). Least Squares Mean Change From Baseline in the 3-Domain Composite Cognition Score (CCS-3D) at Week 104
    Description
    CCS-3D is composed of individual cognitive tests, grouped into 3 domains: 1) episodic memory; 2) executive function; and 3) attention/processing speed. For each cognitive test, a z-score (Z) is calculated at each time point [Z = (observed value - study population mean at baseline) / study population standard deviation at baseline]. These individual Zs are first combined into domain-specific Zs, and then into a composite Z, (i.e. CCS-3D). Theoretically, 99.9% of CCS-3D will be ± 3; more positive CCS-3D indicate greater cognitive impairment relative to the total study population at baseline. Further, negative changes in CCS-3D over time indicate improved cognition relative to the total study population at baseline.
    Time Frame
    Baseline and Week 104 in Part 1
    Title
    Part 1 (Base Study). Least Squares Mean Percent Change From Baseline in Total Hippocampal Volume (THV) at Week 104
    Description
    Least squares mean percent change from baseline at week 104 was calculated for THV as measured by volumetric magnetic resonance imaging (vMRI). Negative percent changes from baseline indicate decreases in THV (i.e. increased hippocampal atrophy).
    Time Frame
    Baseline and Week 104 in Part 1
    Title
    Part 1 (Base Study). Least Squares Mean Change From Baseline in Composite Cortical Amyloid Standard Uptake Value Ratio (SUVR) Assessed With Amyloid Tracer [18F]Flutemetamol Using Positron Emission Tomography (PET) Imaging at Week 104
    Description
    [18F]Flutemetamol PET SUVR measures brain cortical amyloid load. The PET tracer [18F]Flutemetamol was given intravenously (IV). After 90 minutes, participants were scanned for 20 minutes. Using the PET scan images, SUVRs, the ratio of tracer signal in a specific region compared to a reference region (RR; subcortical white matter) are calculated for brain regions of interest (ROIs). SUVRs from a selected set of brain regions are averaged to compute a composite SUVR. Higher composite SUVR values indicate increased amyloid load in selected brain regions, with negative changes in composite cortical SUVR over time indicating decreases in brain amyloid load.
    Time Frame
    Baseline and Week 104 in Part 1
    Title
    Part 1 (Base Study). Least Squares Mean Change From Baseline in Alzheimer's Disease Cooperative Study-Activities of Daily Living Inventory (Mild Cognitive Impairment Version) (ADCS-ADL MCI) Score at Week 104
    Description
    Least squares mean change from baseline at week 104 was assessed for the ADCS-ADL MCI score. The ADCS-ADL MCI is an 18-item assessment of recent, observed performance of activities of daily living administered to participants' trial partners in an interview format. For the 18 items, scores range from 0 (no independence) to (depending on the item) either 2 (5 items), 3 (9 items), or 4 (4 items), with higher scores indicating greater independence in activity performance. Scores from individual items sum to a total ADCS-ADL score (range: 0-53). Lower scores indicate less independence in activity performance and, as a result, greater AD severity. Further, increases in AD severity over time would be reflected by decreases in ADCS-ADL score.
    Time Frame
    Baseline and Week 104 in Part 1
    Title
    Part 1 (Base Study). Mean Percent Change From Baseline in Cerebrospinal Fluid (CSF) Total Tau Concentration at Week 104
    Description
    Mean percent change from baseline at week 104 was calculated for Total Tau concentration in CSF, a measure of brain tau pathology. Per protocol, CSF Total Tau concentration was analyzed as part of a substudy in Part 1, with testing occurring only at select trial sites.
    Time Frame
    Baseline and Week 104 in Part 1

    10. Eligibility

    Sex
    All
    Minimum Age & Unit of Time
    50 Years
    Maximum Age & Unit of Time
    85 Years
    Accepts Healthy Volunteers
    No
    Eligibility Criteria
    Inclusion Criteria: Diagnosis of prodromal AD, including the following: History of subjective memory decline with gradual onset and slow progression for at least one year corroborated by an informant, Objective impairment in episodic memory by memory test performed at Screening, Does not meet criteria for dementia, AND Positive Screening amyloid imaging PET scan using [18F]flutametamol tracer or positive Screening CSF tau:amyloid-β42 (Aβ42) ratio (Participants with a prior positive amyloid imaging PET scan or a Screening PET scan with florbetaben or florbetapir may be enrolled without a Screening flutemetamol scan with Sponsor approval) Able to read at a 6th grade level or equivalent If participant is receiving an acetylcholinesterase inhibitor or memantine, the dose must have been stable for at least three months before Screening Must have a reliable and competent trial partner/informant who has a close relationship with the participant and is willing to accompany the participant to all required trial visits, and to monitor compliance of the administration of the trial medication Inclusion Criteria for Extension Period (Part 2): Tolerated study drug and completed the initial 104-week period of the trial (Part 1) Participant must have a reliable and competent trial partner who must have a close relationship with the subject Exclusion Criteria: History of stroke Evidence of a clinically relevant neurological disorder other than the disease being studied (i.e., prodromal AD) History of seizures or epilepsy within the last 5 years Evidence of a clinically relevant or unstable psychiatric disorder, excluding major depression in remission Participant is at imminent risk of self-harm or of harm to others History of alcoholism or drug dependency/abuse within the last 5 years before Screening Participant does not have a magnetic resonance imaging (MRI) scan obtained within 12 months of Screening and is unwilling or not eligible to undergo an MRI scan at the Screening Visit. With Sponsor approval, a head computed tomography (CT) scan may be substituted for MRI scan to evaluate eligibility History of hepatitis or liver disease that has been active within the 6 months prior to Screening Recent or ongoing, uncontrolled, clinically significant medical condition within 3 months of Screening History of malignancy occurring within the 5 years before Screening, except for adequately treated basal cell or squamous cell skin cancer, in situ cervical cancer, or localized prostate carcinoma Clinically significant vitamin B12 or folate deficiency in the 6 months before Screening Use of any investigational drugs or participation in clinical trials within the 30 days before Screening History of a hypersensitivity reaction to more than three drugs Has human immunodeficiency virus (HIV) by medical history Participant is unwilling or has a contraindication to undergo PET scanning including but not limited to claustrophobia, excessive weight or girth History or current evidence of long QT syndrome, corrected QT (QTc) interval ≥470 milliseconds (for male participants) or ≥480 milliseconds (for female participants), or torsades de pointes Close family member (including the trial partner, spouse or children) who is among the personnel of the investigational or sponsor staff directly involved with this trial Exclusion Criteria for Extension Period (Part 2): Participant is at imminent risk of self-harm or of harm to others Has developed a recent or ongoing, uncontrolled, clinically significant medical or psychiatric condition Results of safety assessments (e.g., laboratory tests) performed in participant at end of Part 1 that are clinically unacceptable to the Investigator Has developed a form of dementia that is not AD Has progressed to dementia due to AD per investigator diagnosis in the initial 104-week study (Part 1). Exclusion Criteria for NFT PET Substudy (Part 2): 1. Had one or two PET scans with MK-6240 in the initial 104-week study.
    Overall Study Officials:
    First Name & Middle Initial & Last Name & Degree
    Medical Director
    Organizational Affiliation
    Merck Sharp & Dohme LLC
    Official's Role
    Study Director

    12. IPD Sharing Statement

    Citations:
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    Citation
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    Citation
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    Results Reference
    derived

    Learn more about this trial

    Efficacy and Safety Trial of Verubecestat (MK-8931) in Participants With Prodromal Alzheimer's Disease (MK-8931-019)

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