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Open-label Extension for Phase 3 Clinical Trials of Simufilam

An Open-label, Long-term Extension Study to Evaluate the Safety and Tolerability of Simufilam 100 mg Tablets in Participants With Mild to Moderate Alzheimer's Disease

Status
Terminated
Phases
Phase 3
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT05575076
Enrollment
1081
Registered
2022-10-12
Start date
2022-11-07
Completion date
2025-01-31
Last updated
2025-05-23

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Alzheimer Disease

Brief summary

The goal of this open-label extension study is to assess long-term safety and tolerability of simufilam 100 mg in subjects who have completed the RETHINK-ALZ or REFOCUS-ALZ Phase 3 clinical trials.

Detailed description

This is a multi-national, multi-center, fixed-dose, 52-week, open-label extension study. After completing participation in either RETHINK-ALZ (PTI-125-06) or REFOCUS-ALZ (PTI-125-07), subjects will have the option to participate in this study. After the subject provides consent and the Investigator confirms the subject satisfies both inclusion and exclusion criteria, the study drug will be administered at the research site on Study Day 1 and subsequent visits will be scheduled. We anticipate up to 1600 subjects may enroll in this study. Approximately up to 150 clinical sites in the USA, Canada, South Korea, and Australia will have the option to participate in this collaborative research effort. For subjects electing to participate, the clinical and laboratory assessments from the Week 76 (REFOCUS-ALZ) or Week 52 (RETHINK-ALZ) End-of-Treatment visit will serve as Baseline Visit assessments for the open-label study on Study Day 1. All subjects will return in 4 weeks and every 12 weeks thereafter for safety assessments. At all post-baseline visits, subjects will report any adverse events since their last visit. In addition to adverse event monitoring, safety will be evaluated at every visit by vital signs, brief examinations, clinical laboratory tests (biochemistry, hematology, and urinalysis) and the Columbia Suicide Severity Rating Scale (C-SSRS). Study drug use since the last visit will be assessed and a new bottle of study drug will be dispensed. The emerging subject safety assessments will be monitored throughout the study by an independent Data Safety Monitoring Board (DSMB).

Interventions

simufilam 100 mg oral tablet, twice daily

Sponsors

Cassava Sciences, Inc.
Lead SponsorINDUSTRY

Study design

Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE

Intervention model description

Open-label extension

Eligibility

Sex/Gender
ALL
Age
51 Years to 89 Years
Healthy volunteers
No

Inclusion criteria

Inclusion Criterion: * Completed RETHINK-ALZ (PTI-125-07) or REFOCUS-ALZ (PTI-125-06). * Clinical presentation continues to be consistent with Alzheimer's disease. * Availability of a study partner.

Exclusion criteria

* Residence in a skilled nursing facility requiring 24-hour care. * Evidence of a neurologic condition other than AD that significantly contributes to the subject's dementia. * Current clinically significant psychiatric diagnosis other than AD. * Unstable, clinically significant medical condition other than AD. * Any medical condition that in the opinion of the investigator may affect safety or ability to complete the study.

Design outcomes

Primary

MeasureTime frameDescription
Number of Participants With Adverse EventsBaseline to 52 weeksTo evaluate the long-term safety and tolerability of simufilam 100 mg tablets in subjects who have completed one of the two double-blind simufilam phase 3 studies.

Countries

Australia, Canada, Puerto Rico, South Korea, United States

Participant flow

Pre-assignment details

This was an open-label extension study.

Participants by arm

ArmCount
Simufilam
simufilam 100 mg oral tablet, twice daily
1,079
Total1,079

Withdrawals & dropouts

PeriodReasonFG000
Overall StudyAdverse Event24
Overall StudyDeath7
Overall StudyLost to Follow-up16
Overall StudyNon-Compliance3
Overall StudyOther17
Overall StudyPhysician Decision6
Overall StudySponsor Requests to be Withdrawn7
Overall StudyStudy Terminated by Sponsor630
Overall StudyWithdrawal by Subject71

Baseline characteristics

CharacteristicSimufilam
Age, Categorical
<=18 years
0 Participants
Age, Categorical
>=65 years
935 Participants
Age, Categorical
Between 18 and 65 years
144 Participants
Age, Continuous73.9 years
STANDARD_DEVIATION 7.77
BMI26.59 kg/m2
STANDARD_DEVIATION 6.892
Ethnicity (NIH/OMB)
Hispanic or Latino
87 Participants
Ethnicity (NIH/OMB)
Not Hispanic or Latino
977 Participants
Ethnicity (NIH/OMB)
Unknown or Not Reported
15 Participants
Race (NIH/OMB)
American Indian or Alaska Native
2 Participants
Race (NIH/OMB)
Asian
45 Participants
Race (NIH/OMB)
Black or African American
54 Participants
Race (NIH/OMB)
More than one race
1 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
2 Participants
Race (NIH/OMB)
Unknown or Not Reported
13 Participants
Race (NIH/OMB)
White
962 Participants
Region of Enrollment
Australia
45 participants
Region of Enrollment
Canada
115 participants
Region of Enrollment
Puerto Rico
7 participants
Region of Enrollment
South Korea
22 participants
Region of Enrollment
United States
890 participants
Sex: Female, Male
Female
583 Participants
Sex: Female, Male
Male
496 Participants

Adverse events

Event typeEG000
affected / at risk
deaths
Total, all-cause mortality
9 / 1,079
other
Total, other adverse events
0 / 1,079
serious
Total, serious adverse events
92 / 1,079

Outcome results

Primary

Number of Participants With Adverse Events

To evaluate the long-term safety and tolerability of simufilam 100 mg tablets in subjects who have completed one of the two double-blind simufilam phase 3 studies.

Time frame: Baseline to 52 weeks

Population: The number of subjects in the analysis (1079) differs by two subjects compared to the Participant Flow module (1081), because there are two subjects who were enrolled but did not receive study treatment and were not included in the Safety Analysis set.

ArmMeasureCategoryValue (COUNT_OF_PARTICIPANTS)
Simufilam 100mgNumber of Participants With Adverse EventsNumber of subjects with mild AEs299 Participants
Simufilam 100mgNumber of Participants With Adverse EventsNumber of subjects with moderate AEs198 Participants
Simufilam 100mgNumber of Participants With Adverse EventsNumber of subjects with severe AEs63 Participants
Simufilam 100mgNumber of Participants With Adverse EventsNumber of subjects with no AEs519 Participants

Source: ClinicalTrials.gov · Data processed: Feb 6, 2026