Characterization of T-Cell Response in Participants Previously Treated With JNJ-54861911 (Atabecestat)

Study Overview
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Brief Summary
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The purpose of this study is to determine T-cell mediated inflammatory immune response in some participants previously exposed to atabecestat.

Detailed Description
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This is an exploratory Phase 0 study in participants who previously participated in studies (54861911ALZ2002 [NCT02260674], 54861911ALZ2003 [NCT02569398], or 54861911ALZ2004 [NCT02406027]) with atabecestat. In this study, participants will only have blood drawn. The primary hypotheses for this study is that adverse event of elevated liver enzymes observed in some participants is caused by a T-cell dependent inflammatory response. Participants will be monitored for adverse events and will be called 1 day after the blood draw to assess for any adverse events.

Official Title
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Characterization of T-Cell Response in Subjects Previously Treated With JNJ-54861911 (Atabecestat)

Conditions
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Alzheimer Disease

Intervention / Treatment
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* Drug: Atabecestat


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Participant who received and discontinued atabecestat in one of the following prior trials (54861911ALZ2002, 54861911ALZ2003, or 54861911ALZ2004) Must sign an informed consent form (ICF) indicating that he or she understands the purpose of, and procedures required for, the study and is willing to participate in the study Willing and able to adhere to the prohibitions and restrictions specified for this study Exclusion Criteria: Anemic based on the last blood draw in the prior atabecestat trial Donated more than (>) 450 milliliter (mL) of blood in the past 3 months Currently participating in an atabecestat study (54861911ALZ2002, 54861911ALZ2003, or 54861911ALZ2004)

Ages Eligible for Study
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Minimum Age: 50 Years
Maximum Age: 85 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Participants with Elevated Liver Enzymes<br>Blood samples will be collected on Day 1 from participants previously treated with atabecestat and who had elevated liver enzymes while on atabecestat. | Drug: Atabecestat<br>* Blood samples will be collected from participants previously treated with atabecestat.<br>* Other names: JNJ-54861911;|
| Active Comparator: Participants Without Elevated Liver Enzymes<br>Blood samples will be collected on Day 1 from participants who completed at least 3 months of dosing with atabecestat and who did not have the elevated liver enzymes (adverse event) while on atabecestat. | Drug: Atabecestat<br>* Blood samples will be collected from participants previously treated with atabecestat.<br>* Other names: JNJ-54861911;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of Participants with Atabecestat-Specific T-cell Mediated Inflammatory Immune Response | Number of Participants with Atabecestat-Specific T-cell Mediated Inflammatory Immune Response (via cluster of differentiation [CD] 4+ T-cells and CD8+ T-cells) will be determined. | Day 1 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Participants T-cell Receptor (TCR) Sequencing | Participants TCR sequencing will be performed to determine if any particular TCR repertoire is associated with a risk of developing an elevation in liver enzymes following exposure to atabecestat. Participants T-cell receptor repertoire will be sequenced via TCR sequencing techniques. | Day 1 |