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PTI-125 for Mild-to-Moderate Alzheimer's Disease


This Phase IIb clinical trial will study the safety and efficacy of the investigational drug PTI-125 in people with mild-to-moderate Alzheimer's disease.

Minimum Age Maximum Age Gender Healthy Volunteers
50 Years 85 Years All No
August 15, 2019
April 15, 2020

  • Diagnosis of dementia due to possible or probable Alzheimer's disease
  • Mini-Mental State Examination score of 16 to 26
  • If female, postmenopausal for at least 1 year
  • Living at home, in a senior residential setting, or other institution without the need for 24-hour nursing care
  • General health acceptable for study participation
  • Fluent in English or Spanish (oral and written)
  • If taking memantine, rivastigmine, or galantamine, must be stable for at least 3 months; if taking donepezil, dose must be less than 23 mg daily
  • Nonsmoker for at least 3 years
  • Must agree to drawing of blood samples and cerebrospinal fluid (lumbar puncture)
  • Ratio of total tau to amyloid-beta 42 in cerebrospinal fluid of 0.28 or greater
  • Caregiver or legal representative who can administer study drug and record time

  • Exposure to an experimental drug, biologic, or medical device within 5 half-lives or 3 months, whichever is longer, before screening
  • Enrollment in previous PTI-125 trial
  • Medical condition that would interfere with a lumbar puncture
  • Residence in a skilled nursing facility and requiring 24-hour care
  • Significant laboratory test results or unstable medical condition
  • Significant untreated hypothyroidism
  • Insufficiently controlled diabetes
  • Renal insufficiency (serum creatinine levels above the upper limit of normal [ULN])
  • Malignant tumor in past 3 years (except squamous and basal cell carcinoma, cervical carcinoma in situ, localized prostate cancer, or localized stage 1 bladder cancer)
  • History of ischemic colitis or enterocolitis
  • Alanine transaminase, aspartate transaminase, or total bilirubin greater than the ULN
  • Heart attack or unstable angina in past 6 months or more than 1 heart attack in past 5 years
  • Significant cardiac arrhythmia (including atrial fibrillation), cardiomyopathy, or cardiac conduction defect (pacemakers are acceptable)
  • Symptomatic low blood pressure or uncontrolled high blood pressure
  • Significant abnormality on screening electrocardiogram, including corrected QT interval of 450 ms or more for males and 470 ms or more for females
  • Stroke in past 18 months or history of a stroke with onset of dementia
  • History of brain tumor or other clinically significant space-occupying lesion on brain imaging 
  • Head trauma with significant loss of consciousness in past year or history of head trauma with onset of dementia
  • Onset of dementia after cardiac arrest, surgery with general anesthesia, or resuscitation
  • Degenerative central nervous system disease other than Alzheimer's disease (e.g., Huntington's disease, Creutzfeldt-Jakob disease, Down's syndrome, frontotemporal dementia, Parkinson's disease)
  • Wernicke's encephalopathy
  • Active acute or chronic central nervous system infection
  • Taking 23 mg or more daily of donepezil currently or within 3 months of randomization
  • Has discontinued acetylcholinesterase inhibitor within 30 days of randomization
  • Prohibited medications: antipsychotics (low doses are allowed if stable for at least 3 months), tricyclic antidepressants and monoamine oxidase inhibitors, anxiolytics or sedative-hypnotics including barbiturates unless given in low doses for benign tremor (low doses of benzodiazepines and zolpidem are allowed), immunosuppressants including systemic corticosteroids if taken in immunosuppressive doses (steroid use for allergy or other inflammation is allowed), antiepileptic medications if taken for control of seizure, opioid-containing analgesics, sedating H1 antihistamines
  • Nicotine therapy, including a patch, varenicline (Chantix), or similar therapeutic agent in 30 days before screening
  • Significant illness within 30 days of enrollment
  • History of significant brain, liver, kidney, endocrine, heart, gastrointestinal, lung, or metabolic disease
  • Positive for serum hepatitis B surface antigen, hepatitis C virus antibody, HIV, or substances of abuse at screening
  • Loss of a significant amount of blood in 4 weeks before the study
  • Suicidal ideation

PTI-125 is a small molecule drug being investigated as a potential treatment to slow or stop Alzheimer's disease. Participants will be randomly assigned to take a tablet of the study drug (50-mg or 100-mg doses) or a placebo twice daily for roughly 1 month. Researchers will measure changes in biomarkers associated with Alzheimer's disease, such as levels of certain abnormal proteins in body fluids, as well as changes in memory.

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Houston Texas 77058 Recruiting Shruti Konda
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McAllen Texas 78504 Recruiting Shruti Konda

Cassava Sciences, Inc.

  • National Institute on Aging (NIA)

Name Role Affiliation
Lindsay Burns, PhD Study Director Cassava Sciences, Inc.

Name Phone Email
Mike Marsman, PharmD 650-224-0694
Carrie Crowley, BA 512-501-2453


A Phase 2b, Randomized, Double-blind, Placebo-controlled, Multiple Dose, Biomarker and Safety Study of PTI-125 in Mild-to-moderate Alzheimer's Disease Patients