GAIN Study
Study Sponsor: Cortexyme

A Novel Approach to the Treatment of Alzheimer’s Disease

GAIN is based on the growing body of scientific evidence that the bacteria P. gingivalis can infect the brain and cause Alzheimer’s disease. 

This clinical trial will evaluate whether Cortexyme’s investigational bacterial protease inhibitor COR388 is safe and effective at halting or slowing the progression of Alzheimer’s diseaseby inactivating the toxic gingipains secreted by the bacteria. Blocking gingipains has been shown to reduce the bacterial load in the brain, reduce amyloid beta levels, reduce markers of neuroinflammation and protect neurons in physiological animal models.3

Cortexyme conducted a 10 day Phase I randomised, double-blind, placebo-controlled, multiple ascending dose  study of COR388 in 24 healthy volunteers. The study also included nine subjects with Alzheimer’s disease, six of whom were administered COR388 and three of whom were given a placebo for 28 days. In these study groups, COR388 was well-tolerated with no clinically significant trends in adverse events or concerning safety signals. DNA of the P. gingivalis bacteria was found in the cerebrospinal fluid in all subjects with Alzheimer’s disease analysed in the study. In addition, there was a promising trend of average improvement in memory tests for COR388 treated Alzheimer’s patients compared to placebo treated patients. See Poster.

There are a growing number of scientific publications linking P. gingivalis to Alzheimer’s disease and development of pathology. 

About GAIN

The GAIN Trial ( is a Phase 2/3 randomised, double-blind, placebo-controlled study that will assess the efficacy, safety, and tolerability of two dose levels of COR388 oral capsules in subjects with probable Alzheimer’s disease dementia according to the National Institute on Ageing-Alzheimer's Association criteria.  Randomised participants will enter a screening period of up to six weeks, a 48-week treatment period and a safety follow-up period of an additional six weeks.  

The GAIN Trial is looking to enrol more than 500 participants at more than 90 clinical trial centres in the United States and Europe. 

3 Dominy et al., Sci. Adv. 2019 January 2019

Gain is Not Actively Enrolling Subjects at This Time

About Cortexyme

Cortexyme (Nasdaq: CRTX) is a clinical stage biopharmaceutical company pioneering a novel disease-modifying therapeutic approach to treat a key underlying cause of Alzheimer’s disease and other degenerative diseases. Cortexyme is targeting a specific, infectious pathogen found in the brain of Alzheimer’s patients and tied to neurodegeneration and neuroinflammation in animal models. The company’s lead investigational medicine, COR388, is the subject of the GAIN trial, an ongoing Phase 2/3 clinical study in patients with mild to moderate Alzheimer’s disease. To learn more about Cortexyme, visit