Safety and Immunogenicity of Repeated Doses of ABvac40 in Patients With a-MCI or Vm-AD

A Multi-center, Randomized, Double-blind, Placebo-controlled, 24 Months Study in Patients With Amnestic Mild Cognitive Impairment or Very Mild Alzheimer's Disease to Investigate the Safety, Tolerability and Immune Response of Repeated Subcutaneous Injections of ABvac40

Alzheimer's disease (AD) is the most common type of dementia, accounting for 50-75% of the estimated 47 million people with dementia worldwide. The amyloid cascade hypothesis of AD proposes that amyloid-β (Aβ) peptide accumulation in the brain, caused by an imbalance between Aβ production and clearance, is the initiating factor of a cascade ultimately leading to dementia.

Aβ peptides are generated from sequential cleavage of the amyloid precursor protein (APP), including Aβ40 and Aβ42. Aβ40 is the predominant variant (90%) among the secreted Aβ forms and although Aβ42 is more hydrophobic and prone to aggregate, and Aβ42 oligomers are regarded to be the most neurotoxic species, Aβ40 can also produce highly toxic diffusible aggregates, which can be prevented in vitro by specific anti-Aβ40 antibodies.

Several studies have proposed that a high concentration of Aβ40 in the brain distinguishes patients with AD from those who have senile plaques but are cognitively normal, pointing to the importance of Aβ40 in the onset of dementia. In keeping with this, previous studies have demonstrated that specific anti-Aβ40 antibodies label NFTs in the entorhinal cortex and the hippocampus of AD brains, and that these do not co-localize with tau NFTs, suggesting the presence of degenerating neuronal populations filled with C-terminal fragments of Aβx-40. In addition, Aβ40 is the main component of amyloid deposition around cerebral arteries causing cerebral amyloid angiopathy (CAA), which has a prevalence of about 80-90% in patients with AD (for more information see Lacosta et al. Alzheimer's Research & Therapy (2018) 10:12 DOI 10.1186/s13195-018-0340-8).

Considering those previous results suggesting that strategies targeting Aβ40 could represent novel disease-modifying therapies, we have developed ABvac40, the first active vaccine targeting the C-terminal end of the Aβ40 peptide.

The purpose of this Phase II study is to confirm in patients with a-MCI or vm-AD the level of safety and tolerability obtained in the ABvac40 Phase I clinical trial in patients with mm-AD. In addition, the study is aimed to better characterize the immune response elicited by ABvac40 and to explore its effects on AD biomarkers.

Study Overview

• Status: Completed
• Conditions: Alzheimer Disease; Mild Cognitive Impairment
• Intervention / Treatment: Biological: ABvac40; Biological: Placebo

• Study Type: Interventional
• Enrollment (Actual): 134
• Phase: Phase 2

Contacts and Locations

Study Locations

• France
  • Montpellier, France, 34295
    • CHU de Montpellier
  • Toulouse, France, 31059
    • Centre de Recherche Clinique du Gérontopôle
  • Bourgogne-Franche-Comté
    • Dijon, Bourgogne-Franche-Comté, France, 21000
      • Hôpital François Mitterrand
• Italy
  • Brescia, Italy, 25125
    • San Giovanni di Dio - Fatebenefratelli
• Spain
  • Alicante
    • Alicante, Alicante, Spain, 03010
      • Hospital General Universitario de Alicante
  • Barcelona
    • Barcelona, Barcelona, Spain, 08025
      • Hospital de la Santa Creu i Sant Pau
    • Barcelona, Barcelona, Spain
      • Hospital del Mar
    • Barcelona, Barcelona, Spain, 08035
      • Hospital Vall d'Hebron
    • Barcelona, Barcelona, Spain, 08005
      • Barcelona Beta Brain Research Center (BBRC)
    • Barcelona, Barcelona, Spain, 08028
      • Fundacio ACE
    • Terrassa, Barcelona, Spain, 08221
      • Hospital Mutua De Terrasa
  • Burgos
    • Burgos, Burgos, Spain, 09006
      • Hospital U. de Burgos
  • Guipuzcoa
    • Donostia / San Sebastian, Guipuzcoa, Spain, 20014
      • Hospital Universitario Donosti
  • La Rioja
    • Logroño, La Rioja, Spain, 26006
      • Hospital San Pedro
  • Lleida
    • Lleida, Lleida, Spain, 25198
      • Hospital Santa Maria de Lleida
  • Madrid
    • Colmenar Viejo, Madrid, Spain, 28034
      • Hospital Ramon y Cajal
    • Madrid, Madrid, Spain, 28040
      • Hospital Clinico San Carlos
    • Madrid, Madrid, Spain, 28006
      • Complejo Hospitalario Ruber Juan Bravo
    • Madrid, Madrid, Spain, 28010
      • Hospital Universitario 12 Octubre
  • Navarre
    • Pamplona, Navarre, Spain, 31008
      • CUN - Clínica Universidad de Navarra
  • Vizcaya
    • Algorta, Vizcaya, Spain, 48993
      • CAE Oroitu
  • Zaragoza
    • Zaragoza, Zaragoza, Spain, 50009
      • Hospital Clinico Universitario Lozano Blesa
• Sweden
  • Stockholm, Sweden, 141 86
    • Karolinska Universitetssjukhuset

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 55 years to 80 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

A subject must meet all the following inclusion criteria:

1. Male or female between 55 and 80 years of age, both inclusive, at the time of signing informed consent.
2. The patient (or legal representative, if applicable) and a close relative/caregiver must read the subject information sheet, agree to participate in the clinical trial and sign the informed consent form (the patient and a close relative/caregiver).
3. Presence of a stable caregiver to attend the patient study visits.
4. Mini-Mental Status Examination (MMSE) score between 24 and 30 points (inclusive), according to age and education level.
5. Clinical Dementia Rating (CDR) scale scoring 0.5.
6. Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) Score on the Delayed Memory Index (DMI) of 85 or lower.
7. The results of the patient's MRI brain scan must be concordant with the diagnosis of clinical a-MCI or vm-AD according to the following criteria: Scheltens scale, and measurement of white matter and past haemorrhages.
8. If the patient is receiving treatment for AD, must have been stable during the two months before the selection visit.
9. Treatment for concomitant diseases must be stable during the previous month before the treatment of the study.
10. Positive assessment of the candidate by the investigator for complying with the requirements and procedures of the study.

Exclusion Criteria:

A subject meeting any of the following exclusion criteria is NOT eligible for participation in the study.

1. Known allergy to components of the vaccine or prior history of anaphylaxis, a severe allergic reaction or a history of hypersensitivity to any component of the formulation. Allergy to fish or shellfish.
2. Active infectious disease (i.e. hepatitis B, C). Positive syphilis serology.
3. History or presence of autoimmune disease, except mild eczema, rhinitis or psoriasis.
4. Presence or history of immunodeficiency (i.e. HIV).
5. Significant kidney and/or liver disease.
6. History of asthma or reactive airway disease with bronchospasm in the last 6 months, or currently on regular treatment.
7. Major uncontrolled systemic condition (e.g. diabetes, congestive heart failure, hypertension).
8. History of cancer (≤5 years since the last specific treatment). Exceptions: basocellular carcinoma.
9. Significant alterations in hematological, biochemical or urine analytical parameters, particularly those relating to levels of vitamin B12, folic acid or thyroid tests.
10. History of any other central nervous system disorder, degenerative or non-degenerative neurological or psychiatric condition that, in the investigator's opinion could be the cause of the dementia, or could explain the cognitive impairment, or that might interfere with cognitive function directly or by its treatment.
11. Geriatric Depression Scale (GDS; abbreviated version), score >5
12. Has a "yes" answer to C-SSRS suicidal ideation items 4 or 5, or any suicidal behavior within 6 months before Screening, or has been hospitalized or treated for suicidal behavior in the past 5 years before Screening.
13. History or signs of cerebrovascular disease (ischemic or haemorrhagic stroke, transient ischemic attack), or diagnosis of possible, probable or clear vascular dementia according to NINDS-AIREN criteria.
14. Presence on MRI of a relevant pattern of microvascular disease (Leukoaraiosis, Fazekas score ≥2 in the deep white matter scale or ≥4 in the global score) or more than one lacunar or territorial infarcts. Any other MRI finding that, in the opinion of the investigator, might be a relevant contributing cause of subject´s cognitive impairment. Presence of up to 3 microhemorrhages will be acceptable.
15. History of bleeding disorder or predisposing conditions, blood clotting or clinically significant abnormal results on coagulation profile at Screening, as determined by the Investigator.
16. Patients being treated with anticoagulants or antiaggregant therapy (aspirin at a prophylactic dose ≤ 325 mg daily or clopidogrel at a dose ≤75 mg daily are allowed) should not be recruited in the study.
17. Modified Hachinski Ischemic Scale, score higher than 4.
18. Surgery (with general anaesthetic) within the previous three months to be included in the trial or programed during the study period.
19. Treatment within 30 days prior to visit 0 with systemic corticosteroids or other immunosuppressant's.
20. Vaccination against influenza or any other vaccination within 2 months before first IMP dose.
21. Patients, who have previously been randomized in this trial.
22. Participation in another clinical trial within the previous 1 month to screening visit, or within the previous 12 months after the last dose to the screening visit in the case of subjects who participated in trials with a study drug whose intention was to modify the progression AD unless documentation of receipt of placebo is available. The patient cannot be included in the study if the experimental drug was an immunotherapeutic drug, including IVIG or a vaccine against Alzheimer's disease unless documentation of receipt of placebo is available.
23. Patients with alcohol or drug abuse or dependence.
24. Absolute (having a pacemaker or implantable defibrillator) or relative (bare metal stent or stent implanted in the last six months) contraindications to MRI examination. Feeling of claustrophobic do not let perform MRI or PET scan.
25. Patients unlikely to comply with the protocol (e.g., unable to return for follow-up visits).
26. Women of childbearing potential, pregnant or nursing.
27. Significant alterations in the EKG that are associated with an added risk for the patient.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: ABvac40; Six administrations of ABvac40; the first five administered once every 4 weeks and the sixth at week 42. Each administration consists of 1mL subcutaneous injection of ABvac40.	Biological: ABvac40; ABvac40 consists in a conjugate of Aβx-40 with a carrier protein (KLH) vehiculated in phosphate buffer containing 0.35% aluminum hydroxide as adjuvant.
Placebo Comparator: Placebo; Six administrations of Placebo; the first five administered once every 4 weeks and the sixth at week 42. Each administration consists of 1mL subcutaneous injection of the vaccine's vehicle buffer without the active component.	Biological: Placebo; Placebo consists in the vaccine's vehicle (phosphate buffer containing 0.35% aluminum hydroxide) without the conjugate.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Average Maximal Increment of Anti-Aβ40 Antibody Signal (Optical Density [OD] in ELISA)	Average maximal increment (MΔ) of plasma anti-Aβ40 antibody signal (optical density [OD] in ELISA) in each subject with regard to Baseline visit.	Part A (Baseline, and post-Baseline visits at Week 2A, Week 6A, Week 10A, Week 14A, Week 18A, Week 24A, Week 40A, Week 44A, Week 50A, Week 77A, and Week 104A)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Subject Discontinuations Due to TEAEs	Number of withdrawn subjects due to treatment-emergent adverse events (TEAEs) during the whole study.	Entire study duration (Week 0 to Week 104 in Part A, and Week 0 to Week 77 in Part B)
Number of Subjects With Clinically Significant Abnormalities in Physical Examination	Clinically significant (CS) abnormalities in physical examination reported during the study.	Entire study duration (Week 0 to Week 104 in Part A, and Week 0 to Week 77 in Part B)
Number of Subjects With Clinically Significant Abnormalities in Neurological Examination	Clinically significant (CS) abnormalities in neurological examination reported during the study.	Entire study duration (Week 0 to Week 104 in Part A, and Week 0 to Week 77 in Part B)
Number of Subjects With Clinically Significant Abnormalities in Analytical Hematology	Clinically significant (CS) abnormalities in hematology parameters reported during the study.	Entire study duration (Week 0 to Week 104 in Part A, and Week 0 to Week 77 in Part B)
Number of Subjects With Clinically Significant Abnormalities in Analytical Biochemistry	Clinically significant (CS) abnormalities in biochemistry parameters reported during the study.	Entire study duration (Week 0 to Week 104 in Part A, and Week 0 to Week 77 in Part B)
Number of Subjects With Clinically Significant Abnormalities in Coagulation	Clinically significant (CS) abnormalities in coagulation parameters reported during the study.	Entire study duration (Week 0 to Week 104 in Part A, and Week 0 to Week 77 in Part B)
Columbia Suicide Severity Rating Scale	Subjects with suicidal ideation or suicidal behavior since last visit.	Part A (Week 24A, Week 50A, Week 77A, and Week 104A)
Level of Anti-Aβ40 Antibodies in CSF	The change in levels of anti-Aβ40 antibodies in cerebrospinal fluid (CSF) from baseline to each applicable post-baseline efficacy visit (Part A) was analyzed using a Mixed-Model Repeated Measures (MMRM), and the ITT analysis set. The MMRM included the recorded outcome value as the dependent variable; treatment, protocol specified visits, treatment-by-visit interaction, and amyloid positivity as the fixed effects; baseline age as covariates; and measures within-patient at each visit as a repeated measure. An unstructured variance-covariance matrix was used. The following factors may also have been included in the model: ApoE carrier status, baseline use of AD symptomatic medication and clinical subgroup - MCI or vmAD, if found to be significantly associated with the response measure (p < 0.15).	Part A (Week 50A and Week 104A)
Level of Anti-Aβ40 Antibodies in Plasma	The change in levels of anti-Aβ40 antibodies in plasma from baseline to each applicable post-baseline efficacy visit (Part A) was analyzed using a Mixed-Model Repeated Measures (MMRM), and the ITT analysis set. The MMRM included the recorded outcome value as the dependent variable; treatment, protocol specified visits, treatment-by-visit interaction, and amyloid positivity as the fixed effects; baseline age as covariates; and measures within-patient at each visit as a repeated measure. A compound symmetric variance-covariance matrix was used. The following factors may also have been included in the model: ApoE carrier status, baseline use of AD symptomatic medication and clinical subgroup - MCI or vmAD, if found to be significantly associated with the response measure (p < 0.15).	Part A (Week 2A, Week 6A, Week 10A, Week 14A, Week 18A, Week 24A, Week 40A, Week 44A, Week 50A, Week 77A, and Week 104A)
Level of Antibody-secreting Cells	The change in levels of antibody-secreting cells from baseline to each applicable post-baseline efficacy visit (Part A) was analyzed using a Mixed-Model Repeated Measures (MMRM), and the ITT analysis set. The MMRM included the recorded outcome value as the dependent variable; treatment, protocol-specified visits, treatment-by-visit interaction, and amyloid positivity as the fixed effects; baseline age as covariates; and measures within-patient at each visit as a repeated measure. An unstructured variance-covariance matrix was used. The following factors may also have been included in the model: ApoE carrier status, baseline use of AD symptomatic medication and clinical subgroup - MCI or vmAD, if found to be significantly associated with the response measure (p < 0.15).	Part A (Week 2A, Week 6A, Week 10A, Week 14A, Week 18A, Week 24A, Week 40A, Week 44A, Week 50A, Week 77A, and Week 104A)
Level of Aβ40 Peptides in Plasma - ABtest-IA	The change in levels of anti-Aβ40 peptides in plasma (ABtest-IA) from baseline to each applicable postbaseline efficacy visit (Part A) was analyzed using a Mixed-Model Repeated Measures (MMRM), and the ITT analysis set. The MMRM included change from baseline in the efficacy parameter as the dependent variable; treatment, protocol-specified visits, treatment-by-visit interaction, and amyloid positivity as the fixed effects; baseline efficacy parameter and baseline age as covariates; and measures within-patient at each visit as a repeated measure. An unstructured variance-covariance matrix was used. The following factors may also have been included in the model: ApoE carrier status, baseline use of AD symptomatic medication and clinical subgroup - MCI or vmAD, if found to be significantly associated with the response measure (p < 0.15).	Part A (Week 2A, Week 6A, Week 10A, Week 14A, Week 18A, Week 24A, Week 40A, Week 44A, Week 50A, Week 77A, and Week 104A)
Level of Aβ42 Peptides in Plasma - ABtest-IA	The change in levels of anti-Aβ42 peptides in plasma (ABtest-IA) from baseline to each applicable postbaseline efficacy visit (Part A) was analyzed using a Mixed-Model Repeated Measures (MMRM), and the ITT analysis set. The MMRM included change from baseline in the efficacy parameter as the dependent variable; treatment, protocol-specified visits, treatment-by-visit interaction, and amyloid positivity as the fixed effects; baseline efficacy parameter and baseline age as covariates; and measures within-patient at each visit as a repeated measure. An unstructured variance-covariance matrix was used. The following factors may also have been included in the model: ApoE carrier status, baseline use of AD symptomatic medication and clinical subgroup - MCI or vmAD, if found to be significantly associated with the response measure (p < 0.15).	Part A (Week 2A, Week 6A, Week 10A, Week 14A, Week 18A, Week 24A, Week 40A, Week 44A, Week 50A, Week 77A, and Week 104A)
Level of Aβ40 Peptides in Plasma - ABtest-MS	The change in levels of anti-Aβ40 peptides in plasma (ABtest-MS) from baseline to each applicable postbaseline efficacy visit (Part A) was analyzed using a Mixed-Model Repeated Measures (MMRM), and the ITT analysis set. The MMRM included change from baseline in the efficacy parameter as the dependent variable; treatment, protocol-specified visits, treatment-by-visit interaction, and amyloid positivity as the fixed effects; baseline efficacy parameter and baseline age as covariates; and measures within-patient at each visit as a repeated measure. A compound symmetric variance-covariance matrix was used. The following factors may also have been included in the model: ApoE carrier status, baseline use of AD symptomatic medication and clinical subgroup - MCI or vmAD, if found to be significantly associated with the response measure (p < 0.15).	Part A (Week 2A, Week 6A, Week 10A, Week 14A, Week 18A, Week 24A, Week 40A, Week 44A, Week 50A, Week 77A, and Week 104A)
Level of Aβ42 Peptides in Plasma - ABtest-MS	The change in levels of anti-Aβ42 peptides in plasma (ABtest-MS) from baseline to each applicable postbaseline efficacy visit (Part A) was analyzed using a Mixed-Model Repeated Measures (MMRM), and the ITT analysis set. The MMRM included change from baseline in the efficacy parameter as the dependent variable; treatment, protocol-specified visits, treatment-by-visit interaction, and amyloid positivity as the fixed effects; baseline efficacy parameter and baseline age as covariates; and measures within-patient at each visit as a repeated measure. An unstructured variance-covariance matrix was used. The following factors may also have been included in the model: ApoE carrier status, baseline use of AD symptomatic medication and clinical subgroup - MCI or vmAD, if found to be significantly associated with the response measure (p < 0.15).	Part A (Week 2A, Week 6A, Week 10A, Week 14A, Week 18A, Week 24A, Week 40A, Week 44A, Week 50A, Week 77A, and Week 104A)
Cortical Fibrillary Amyloid Deposition Assessed by a-PET Scans	The change in amyloid-PET (a-PET) standard centiloid global cortical area (reference Pons) from baseline to each applicable post-baseline efficacy visit (Part A) was analyzed using a Mixed-Model Repeated Measures (MMRM), and the ITT analysis set. The MMRM included change from baseline in the efficacy parameter as the dependent variable; treatment, protocol-specified visits, treatment-by-visit interaction, and amyloid positivity as the fixed effects; baseline efficacy parameter and baseline age as covariates; and measures within-patient at each visit as a repeated measure. An unstructured variance-covariance matrix was used. The following factors may also have been included in the model: ApoE carrier status, baseline use of AD symptomatic medication and clinical subgroup - MCI or vmAD, if found to be significantly associated with the response measure (p < 0.15).	Part A (Week 50A and Week 104A)
Percentage of Change in Brain Volume	The percent change in brain volume from baseline to each applicable post-baseline efficacy visit (Part A) was analyzed using a Mixed-Model Repeated Measures (MMRM), and the ITT analysis set. The MMRM included change from baseline in the efficacy parameter as the dependent variable; treatment, protocol-specified visits, treatment-by-visit interaction, and amyloid positivity as the fixed effects; baseline efficacy parameter and baseline age as covariates; and measures within-patient at each visit as a repeated measure. An unstructured variance-covariance matrix was used. The following factors may also have been included in the model: ApoE carrier status, baseline use of AD symptomatic medication and clinical subgroup - MCI or vmAD, if found to be significantly associated with the response measure (p < 0.15).	Part A (Week 24A, Week 50A, and Week 104A)
Percentage of Change in Hippocampal Volume	The percent change in right and left hippocampal volume from baseline to each applicable post-baseline efficacy visit (Part A) was analyzed using a Mixed-Model Repeated Measures (MMRM), and the ITT analysis set. The MMRM included change from baseline in the efficacy parameter as the dependent variable; treatment, protocol-specified visits, treatment-by-visit interaction, and amyloid positivity as the fixed effects; baseline efficacy parameter and baseline age as covariates; and measures within-patient at each visit as a repeated measure. An unstructured variance-covariance matrix was used. The following factors may also have been included in the model: ApoE carrier status, baseline use of AD symptomatic medication and clinical subgroup - MCI or vmAD, if found to be significantly associated with the response measure (p < 0.15).	Part A (Week 24A, Week 50A, Week 104A)
Percentage of Change in Ventricular Volume	The percent change in ventricular volume from baseline to each applicable post-baseline efficacy visit (Part A) was analyzed using a Mixed-Model Repeated Measures (MMRM), and the ITT analysis set. The MMRM included change from baseline in the efficacy parameter as the dependent variable; treatment, protocol-specified visits, treatment-by-visit interaction, and amyloid positivity as the fixed effects; baseline efficacy parameter and baseline age as covariates; and measures within-patient at each visit as a repeated measure. An unstructured variance-covariance matrix was used. The following factors may also have been included in the model: ApoE carrier status, baseline use of AD symptomatic medication and clinical subgroup - MCI or vmAD, if found to be significantly associated with the response measure (p < 0.15).	Part A (Week 24A, Week 50A, and Week 104A)
Level of Aβ42 Peptides in CSF	The change in levels of Aβ42 peptides in cerebrospinal fluid (CSF) from baseline to each applicable postbaseline efficacy visit (Part A) was analyzed using a Mixed-Model Repeated Measures (MMRM), and the ITT analysis set. The MMRM included change from baseline in the efficacy parameter as the dependent variable; treatment, protocol-specified visits, treatment-by-visit interaction, and amyloid positivity as the fixed effects; baseline efficacy parameter and baseline age as covariates; and measures within-patient at each visit as a repeated measure. An unstructured variance-covariance matrix was used. The following factors may also have been included in the model: ApoE carrier status, baseline use of AD symptomatic medication and clinical subgroup - MCI or vmAD, if found to be significantly associated with the response measure (p < 0.15).	Part A (Week 50A and Week 104A)
Level of Aβ40 Peptides in CSF	The change in levels of Aβ40 peptides in cerebrospinal fluid (CSF) from baseline to each applicable postbaseline efficacy visit (Part A) was analyzed using a Mixed-Model Repeated Measures (MMRM), and the ITT analysis set. The MMRM included change from baseline in the efficacy parameter as the dependent variable; treatment, protocol-specified visits, treatment-by-visit interaction, and amyloid positivity as the fixed effects; baseline efficacy parameter and baseline age as covariates; and measures within-patient at each visit as a repeated measure. An unstructured variance-covariance matrix was used. The following factors may also have been included in the model: ApoE carrier status, baseline use of AD symptomatic medication and clinical subgroup - MCI or vmAD, if found to be significantly associated with the response measure (p < 0.15).	Part A (Week 50A and Week 104A)
Aβ42/Aβ40 Ratio in CSF	The change in Aβ42/Aβ40 ratio in cerebrospinal fluid (CSF) from baseline to each applicable postbaseline efficacy visit (Part A) was analyzed using a Mixed-Model Repeated Measures (MMRM), and the ITT analysis set. The MMRM included change from baseline in the efficacy parameter as the dependent variable; treatment, protocol-specified visits, treatment-by-visit interaction, and amyloid positivity as the fixed effects; baseline efficacy parameter and baseline age as covariates; and measures within-patient at each visit as a repeated measure. An unstructured variance-covariance matrix was used. The following factors may also have been included in the model: ApoE carrier status, baseline use of AD symptomatic medication and clinical subgroup - MCI or vmAD, if found to be significantly associated with the response measure (p < 0.15).	Part A (Week 50A and Week 104A)
Level of Total Tau in CSF	The change in levels of total Tau in cerebrospinal fluid (CSF) from baseline to each applicable postbaseline efficacy visit (Part A) was analyzed using a Mixed-Model Repeated Measures (MMRM), and the ITT analysis set. The MMRM included change from baseline in the efficacy parameter as the dependent variable; treatment, protocol-specified visits, treatment-by-visit interaction, and amyloid positivity as the fixed effects; baseline efficacy parameter and baseline age as covariates; and measures within-patient at each visit as a repeated measure. An unstructured variance-covariance matrix was used. The following factors may also have been included in the model: ApoE carrier status, baseline use of AD symptomatic medication and clinical subgroup - MCI or vmAD, if found to be significantly associated with the response measure (p < 0.15).	Part A (Week 50A and Week 104A)
Level of p-Tau 181 in CSF	The change in levels of p-Tau 181 in cerebrospinal fluid (CSF) from baseline to each applicable post-baseline efficacy visit (Part A) was analyzed using a Mixed-Model Repeated Measures (MMRM), and the ITT analysis set. The MMRM included change from baseline in the efficacy parameter as the dependent variable; treatment, protocol-specified visits, treatment-by-visit interaction, and amyloid positivity as the fixed effects; baseline efficacy parameter and baseline age as covariates; and measures within-patient at each visit as a repeated measure. An unstructured variance-covariance matrix was used. The following factors may also have been included in the model: ApoE carrier status, baseline use of AD symptomatic medication and clinical subgroup - MCI or vmAD, if found to be significantly associated with the response measure (p < 0.15).	Part A (Week 50A and Week 104A)
Level of Neurofilament Light in CSF	The change in levels of neurofilament light in cerebrospinal fluid (CSF) from baseline to each applicable post-baseline efficacy visit (Part A) was analyzed using a Mixed-Model Repeated Measures (MMRM), and the ITT analysis set. The MMRM included change from baseline in the efficacy parameter as the dependent variable; treatment, protocol-specified visits, treatment-by-visit interaction, and amyloid positivity as the fixed effects; baseline efficacy parameter and baseline age as covariates; and measures within-patient at each visit as a repeated measure. An unstructured variance-covariance matrix was used. The following factors may also have been included in the model: ApoE carrier status, baseline use of AD symptomatic medication and clinical subgroup - MCI or vmAD, if found to be significantly associated with the response measure (p < 0.15).	Part A (Week 50A and Week 104A)
Level of Neurogranin in CSF	The change in levels of neurogranin in cerebrospinal fluid (CSF) from baseline to each applicable post-baseline efficacy visit (Part A) was analyzed using a Mixed-Model Repeated Measures (MMRM), and the ITT analysis set. The MMRM included change from baseline in the efficacy parameter as the dependent variable; treatment, protocol-specified visits, treatment-by-visit interaction, and amyloid positivity as the fixed effects; baseline efficacy parameter and baseline age as covariates; and measures within-patient at each visit as a repeated measure. An unstructured variance-covariance matrix was used. The following factors may also have been included in the model: ApoE carrier status, baseline use of AD symptomatic medication and clinical subgroup - MCI or vmAD, if found to be significantly associated with the response measure (p < 0.15).	Part A (Week 50A and Week 104A)
Mini Mental State Examination (MMSE) Score	The change in MMSE score from baseline to each applicable post-baseline efficacy visit (Part A) was analyzed using a MMRM and the ITT analysis set. MMSE is an 11-question measure that tests 5 areas of cognitive function: orientation, registration, attention and calculation, recall, and language. MMSE score ranges: 0-30, with lower scores indicating worst cognition. The MMRM included change from baseline in the efficacy parameter as the dependent variable; treatment, protocol-specified visits, treatment-by-visit interaction, and amyloid positivity as the fixed effects; baseline efficacy parameter and baseline age as covariates; and measures within-patient at each visit as a repeated measure. An unstructured variance-covariance matrix was used. The following factors may also have been included in the model: ApoE carrier status, baseline use of AD symptomatic medication and clinical subgroup - MCI or vmAD, if found to be significantly associated with the response measure (p < 0.15).	Part A (baseline, and post-baseline at Week 24A, Week 50A, Week 77A, and Week 104A)
Clinical Dementia Rating-Sum of Boxes (CDR-SB) Score	The change in CDR-SB score from baseline to each applicable post-baseline efficacy visit (Part A) was analyzed using a MMRM and the ITT analysis set. CDR-SB assesses 6 cognitive and functional domains: Memory, Orientation, Judgment & Problem Solving, Community Affairs, Home & Hobbies, Personal Care. CDR-SB score ranges: 0-18. The higher scores mean a worst outcome. The MMRM included change from baseline in the efficacy parameter as the dependent variable; treatment, protocol-specified visits, treatment-by-visit interaction, and amyloid positivity as the fixed effects; baseline efficacy parameter and baseline age as covariates; and measures within-patient at each visit as a repeated measure. An unstructured variance-covariance matrix was used. The following factors may also have been included in the model: ApoE carrier status, baseline use of AD symptomatic medication and clinical subgroup - MCI or vmAD, if found to be significantly associated with the response measure (p < 0.15).	Part A (Week 24A, Week 50A, Week 77A, and Week 104A)
Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) Score	The change in RBANS total score from baseline to each applicable post-baseline efficacy visit (Part A) was analyzed using a MMRM and the ITT analysis set. RBANS assesses 5 cognitive domains: Immediate Memory, Visuospatial/constructional, Language, Attention, Delayed Memory. Total score (range 40-160) sums the 5 domain scores. The higher scores mean a better outcome. The MMRM included change from baseline in the efficacy parameter as the dependent variable; treatment, protocol-specified visits, treatment-by-visit interaction, and amyloid positivity as the fixed effects; baseline efficacy parameter and baseline age as covariates; and measures within-patient at each visit as a repeated measure. An unstructured variance-covariance matrix was used. The following factors may also have been included in the model: ApoE carrier status, baseline use of AD symptomatic medication and clinical subgroup - MCI or vmAD, if found to be significantly associated with the response measure (p < 0.15).	Part A (Week 24A, Week 50A, Week 77A, and Week 104A)
Alzheimer's Disease Cooperative Study - Activities of Daily Living, Mild Cognitive Impairment (ADCS-ADL MCI) Score	The change in ADCS-ADL MCI total score from baseline to each applicable post-baseline efficacy visit (Part A) was analyzed using a MMRM and the ITT analysis set. ADCS-ADL MCI is a 24-item scale that includes 6 basic activities of daily living (ADL) items and 16 instrumental ADL items that provide a total score: 0-78, with a lower score indicating greater severity. The MMRM included change from baseline in the efficacy parameter as the dependent variable; treatment, protocol-specified visits, treatment-by-visit interaction, and amyloid positivity as the fixed effects; baseline efficacy parameter and baseline age as covariates; and measures within-patient at each visit as a repeated measure. An unstructured variance-covariance matrix was used. The following factors may also have been included in the model: ApoE carrier status, baseline use of AD symptomatic medication and clinical subgroup - MCI or vmAD, if found to be significantly associated with the response measure (p < 0.15).	Part A (Week 24A, Week 50A, Week 77A, and Week 104A)
Trail Making Test (TMT) Scores	Change in TMT score from baseline to each applicable post-baseline efficacy visit (Part A) was analyzed using a MMRM and the ITT analysis set. TMT has 2 parts in which the patient connects 25 dots in order as quickly as possible. In TMT-A, targets are numbers 1-25; in TMT-B, targets are numbers 1-13 interleaved with letters A-L. Lower timings indicate better outcome. The MMRM included change from baseline in the efficacy parameter as the dependent variable; treatment, protocol-specified visits, treatment-by-visit interaction, and amyloid positivity as the fixed effects; baseline efficacy parameter and baseline age as covariates; and measures within-patient at each visit as a repeated measure. An unstructured variance-covariance matrix was used. The following factors may also have been included in the model: ApoE carrier status, baseline use of AD symptomatic medication and clinical subgroup - MCI or vmAD, if found to be significantly associated with the response measure (p < 0.15).	Part A (Week 24A, Week 50A, Week 77A, and Week 104A)
Investigator Global Evaluation (IGE) Score	Change in IGE from baseline to each applicable post-baseline efficacy visit (Part A) was analyzed using MMRM and ITT analysis set. IGE at baseline:1-Good general status;2-Slight deterioration;3-Moderate deterioration;4-Bad general status. IGE after baseline:1-Marked improvement;2-Moderate improvement;3-Slight improvement;4-No change;5-Slight worsening;6-Moderate worsening;7-Marked worsening. MMRM included IGE after baseline as the dependent variable; treatment, protocol-specified visits, treatment-by-visit interaction, and amyloid positivity as the fixed effects; baseline efficacy parameter and baseline age as covariates; and measures within-patient at each visit as a repeated measure. An unstructured variance-covariance matrix is used. Following factors may also have been included in the model: ApoE carrier status, baseline use of AD symptomatic medication and clinical subgroup - MCI or vmAD, if found to be significantly significantly associated with response measure (p < 0.15).	Part A (Week 24A, Week 50A, and Week 104A)
EuroQol 5 Dimensions 5 Levels (EQ-5D-5L) Overall Severity Index Score	Change in EQ-5D-5L overall severity index from baseline to each applicable post-baseline efficacy visit (Part A) was analyzed using MMRM and ITT analysis set. EQ-5D-5L has 5 dimensions: mobility, self-care, usual activities, pain/discomfort, anxiety/depression; rated: 1=no problems, 2=slight problems, 3=moderate problems, 4=severe problems, and 5=extreme problems. The MMRM included change from baseline in the efficacy parameter as the dependent variable; treatment, protocol-specified visits, treatment-by-visit interaction, and amyloid positivity as the fixed effects; baseline efficacy parameter and baseline age as covariates; and measures within-patient at each visit as a repeated measure. An unstructured variance-covariance matrix was used. The following factors may also have been included in the model: ApoE carrier status, baseline use of AD symptomatic medication and clinical subgroup - MCI or vmAD, if found to be significantly associated with the response measure (p < 0.15).	Part A (Week 50A and Week 104A)
EuroQol 5 Dimensions 5 Levels - Visual Analogue Scale (EQ-5D-5L - VAS) Score	The change in EQ-5D-5L - VAS score from baseline to each applicable post-baseline efficacy visit (Part A) was analyzed using a Mixed-Model Repeated Measures (MMRM), and the ITT analysis set. VAS records the patient's self-rated health on a vertical scale, ranging from 100 = 'Best imaginable health state' down to 0 = 'Worst imaginable health state'. The MMRM included change from baseline in the efficacy parameter as the dependent variable; treatment, protocol-specified visits, treatment-by-visit interaction, and amyloid positivity as the fixed effects; baseline efficacy parameter and baseline age as covariates; and measures within-patient at each visit as a repeated measure. An unstructured variance-covariance matrix was used. The following factors may also have been included in the model: ApoE carrier status, baseline use of AD symptomatic medication and clinical subgroup - MCI or vmAD, if found to be significantly associated with the response measure (p < 0.15).	Part A (Week 50A and Week 104A)

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Average Maximal Increment of Anti-Aβ40 Antibody Signal (Optical Density [OD] in ELISA) - Sensitivity	Average maximal increment (MΔ) of plasma anti-Aβ40 antibody signal (optical density [OD] in ELISA) in each subject with regard to Baseline visit. Sensitivity analyses in the PP (Part A) analysis set.	Part A (Baseline, and post-Baseline visits at Week 2A, Week 6A, Week 10A, Week 14A, Week 18A, Week 24A, Week 40A, Week 44A, Week 50A, Week 77A, and Week 104A)

Collaborators and Investigators

• Sponsor: Araclon Biotech S.L.
• Investigators: Study Director: Manuel Sarasa, Araclon Biotech Ltd

Publications and helpful links

General Publications

• Pascual-Lucas M, Lacosta AM, Montanes M, Canudas J, Loscos J, Monleon I, Allue JA, Sarasa L, Fandos N, Romero J, Sarasa M, Torres M, Whyms D, Terencio J, Pinol-Ripoll G, Boada M. Safety, tolerability, immunogenicity, and efficacy of ABvac40 active immunotherapy against Abeta40 in patients with mild cognitive impairment or very mild Alzheimer's disease: A randomized, double-blind, placebo-controlled phase 2 study. Alzheimers Dement. 2025 Oct;21(10):e70776. doi: 10.1002/alz.70776.

Study record dates

Study Major Dates

• Study Start (Actual): December 13, 2017
• Primary Completion (Actual): March 23, 2023
• Study Completion (Actual): March 23, 2023

Study Registration Dates

• First Submitted: March 2, 2018
• First Submitted That Met QC Criteria: March 8, 2018
• First Posted (Actual): March 12, 2018

Study Record Updates

• Last Update Posted (Actual): May 5, 2026
• Last Update Submitted That Met QC Criteria: April 15, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Mental Disorders; Neurocognitive Disorders; Cognition Disorders; Dementia; Tauopathies; Neurodegenerative Diseases; Cognitive Dysfunction; Alzheimer Disease
• Other Study ID Numbers: AB1601

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No