TerminatedPhase 3Results posted

A Study to Evaluate the Safety and Tolerability of Long-term Administration of Gantenerumab in Participants With Alzheimer's Disease (AD)

An Open-Label, Multicenter, Rollover Study to Evaluate the Safety and Tolerability of Long-Term Administration of Gantenerumab in Participants With Alzheimer's Disease

Lead sponsor

Hoffmann-La Roche

Asset

Gantenerumab

Listed sites

Recruiting sites

Enrollment

116

actual

Study population

Alzheimer’s disease

Key I/E criterion

Primary endpoints

•Adverse Events (AEs) and Serious Adverse Events (SAEs)•Any Suicidal Ideation or Behavior•Amyloid-Related Imaging Abnormalities-Edema (ARIA-E) AEs

Footprint

Where this trial recruits

Site locations as reported to ClinicalTrials.gov. Site count is not enrollment count; per-site enrollment is not available from source.

Identifiers

Registered as

NCT IDNCT04339413

Org study IDWN41874

Timeline

Milestones

Study first posted2020-04-09actual

Study start2020-05-22actual

Primary completion2023-01-04actual

Study completion2023-01-04actual

Last update posted2024-01-18actual

Results first posted2024-01-18actual

Assets

Drug assets

Gantenerumab

Study populations

Who this study enrolls

Alzheimer’s disease

Eligibility

Who can enroll

SexAll

Healthy volunteersNot accepted

Inclusion criteria

•Part 1: Participants who completed the open-label extensions (OLEs) of studies WN25203 or WN28745 will be eligible to participate in Part 1 of the study

•Part 2: All participants who have completed Week 104 visit in Part 1 will be eligible for Part 2 of the study

•For Part 1 and Part 2:

•For women of childbearing potential: agreement to remain abstinent (refrain from heterosexual intercourse) or use contraceptive methods that result in a failure rate of <1% per year during the treatment period and for at least 16 weeks after the last dose of study drug

•Agreement to not donate blood or blood products for transfusion for the duration of the study and for 1 year after final dose of study drug

•Availability of a person ('caregiver') who in the investigator's judgement, has frequent and sufficient contact with the participant

Exclusion criteria

•Prematurely discontinued from the OLEs of studies WN25203 or WN28745 or from study drug for any reason

•Any medical condition that may jeopardize the participant's safety if he or she continues to receive study treatment

•If the participant is unlikely to benefit from gantenerumab therapy, based on disease progression or other factors, or if study participation is otherwise not in the participant's best interest

•Any investigational treatment other than gantenerumab during or since completion of the OLEs of studies WN25203 or WN28745

•Pregnancy

•Evidence of disseminated leptomeningeal hemosiderosis (i.e., more than three focal leptomeningeal hemosiderosis)

•Evidence of intracerebral macrohemorrhage

•Part 2: Participants who have been discontinued from Part 1 of the study

Endpoints (14)

What's being measured

Protocol endpoints and posted registry outcome measures, grouped into outcome categories. Composite endpoints show their component event types. Standard codes (LOINC, SNOMED CT) are shown where available.

Coverage by outcome category

Amyloid biomarkers

Safety / tolerability / PK

Other (unclassified)

Behavior / neuropsychiatric

2 endpoints

Primary/protocol endpoint

Number of Participants With Change in Any Suicidal Ideation or Behavior as Assessed by Columbia-Suicide Severity Rating Scale (C-SSRS)

Time frame:Baseline (Day 1), up to Week 104

change from baseline, improvement

Primary/registry result

Number of Participants With Change in Any Suicidal Ideation or Behavior as Assessed by Columbia-Suicide Severity Rating Scale (C-SSRS)

Time frame:Baseline (Day 1), up to Week 104

change from baseline, improvement

Posted result

Group	Value (count_of_participants), Participants	Reported bounds
SCarlet RoADBaselinen=56 Participants	3	-
Week 24n=52 Participants	2	-
Week 52n=48 Participants	1	-
Week 76n=37 Participants	0	-
Week 104n=30 Participants	0	-
Marguerite RoADBaselinen=54 Participants	0	-
Week 24n=44 Participants	0	-
Week 52n=38 Participants	0	-
Week 76n=32 Participants	1	-
Week 104n=0 Participants	0	-

Amyloid biomarkers

4 endpoints

Primary/protocol endpoint

Number of Participants With Amyloid-Related Imaging Abnormalities-Edema (ARIA-E) AEs

Time frame:Baseline [Day 1] up to 4 weeks after the last dose of study drug (Up to Week 133)

event count, event

Primary/protocol endpoint

Number of Participants With Amyloid-Related Imaging Abnormalities-Haemosiderin Deposition (ARIA-H) AEs

Time frame:Baseline [Day 1] up to 4 weeks after the last dose of study drug (Up to Week 133)

event count, event

Primary/registry result

Number of Participants With Amyloid-Related Imaging Abnormalities-Edema (ARIA-E) AEs

Time frame:Baseline [Day 1] up to 4 weeks after the last dose of study drug (Up to Week 133)

event count, event

Posted result

Group	Value (count_of_participants), Participants	Reported bounds
SCarlet RoADn=59 Participants	0	-
Marguerite RoADn=56 Participants	0	-

Primary/registry result

Number of Participants With Amyloid-Related Imaging Abnormalities-Haemosiderin Deposition (ARIA-H) AEs

Time frame:Baseline [Day 1] up to 4 weeks after the last dose of study drug (Up to Week 133)

event count, event

Posted result

Group	Value (count_of_participants), Participants	Reported bounds
SCarlet RoADn=59 Participants	0	-
Marguerite RoADn=56 Participants	0	-

Safety / tolerability / PK

4 endpoints

Primary/protocol endpoint

Number of Participants With Adverse Events (AEs) and Serious Adverse Events (SAEs)

Time frame:Baseline [Day 1] up to 4 weeks after the last dose of study drug (Up to Week 133)

event count, event

Primary/protocol endpoint

Number of Participants Who Discontinued Treatment Due to AEs

Time frame:Baseline [Day 1] up to 4 weeks after the last dose of study drug (Up to Week 133)

event count, event

Primary/registry result

Number of Participants With Adverse Events (AEs) and Serious Adverse Events (SAEs)

Time frame:Baseline [Day 1] up to 4 weeks after the last dose of study drug (Up to Week 133)

event count, event

Posted result

Group	Value (count_of_participants), Participants	Reported bounds
SCarlet RoADAEn=59 Participants	54	-
SAEn=59 Participants	11	-
Marguerite RoADAEn=56 Participants	49	-
SAEn=56 Participants	10	-

Primary/registry result

Number of Participants Who Discontinued Treatment Due to AEs

Time frame:Baseline [Day 1] up to 4 weeks after the last dose of study drug (Up to Week 133)

event count, event

Posted result

Group	Value (count_of_participants), Participants	Reported bounds
SCarlet RoADn=59 Participants	3	-
Marguerite RoADn=56 Participants	0	-

Other (unclassified)

4 endpoints

Primary/protocol endpoint/low confidence

Number of Participants With Anti-drug Antibody (ADA) to Gantenerumab

Time frame:Up to Week 133

event count, event

Primary/protocol endpoint/low confidence

Number of Participants With Injection-Site Reactions

Time frame:Baseline [Day 1] up to 4 weeks after the last dose of study drug (Up to Week 133)

event count, event

Primary/registry result/low confidence

Number of Participants With Anti-drug Antibody (ADA) to Gantenerumab

Time frame:Up to Week 133

event count, event

Posted result

Group	Value (count_of_participants), Participants	Reported bounds
SCarlet RoADn=59 Participants	3	-
Marguerite RoADn=56 Participants	1	-

Primary/registry result/low confidence

Number of Participants With Injection-Site Reactions

Time frame:Baseline [Day 1] up to 4 weeks after the last dose of study drug (Up to Week 133)

event count, event

Posted result

Group	Value (count_of_participants), Participants	Reported bounds
SCarlet RoADn=59 Participants	14	-
Marguerite RoADn=56 Participants	7	-

Provenance

Sources

Trial identity, design, statusClinicalTrials.gov API v2

Snapshot dateJuly 21, 2026

Endpoint classificationDelfa ADRD endpoint taxonomy

Results tableClinicalTrials.gov results section

Trial facts come from public ClinicalTrials.gov records. Endpoint categories are Delfa's classification of those records, not a ClinicalTrials.gov field. All figures reflect the July 21, 2026 snapshot.