There is one clinical trial.
This will be a two-center, placebo controlled blinded clinical trial to evaluate the safety and tolerability of efavirenz (EFV) in 36 clinically stable subjects with mild cognitive impairment/early dementia due to Alzheimer's Disease (AD) age ≥55 years. Of these 36 total subjects, 18 will be recruited by MGH and 18 will be recruited by UH. A subset of the subjects at MGH only will also participate in a Stable Isotope Labeling Kinetics (SILK) protocol with deuterated water (a nonhazardous substance), designed to more precisely measure EFV effects on CNS cholesterol turnover. Each respective site's 18 total recruited individuals will be divided into 3 groups: these 3 groups will represent two particular dosages of EFV and a placebo group, respectively. In a double-blind fashion, participants will be receiving either a capsule of EFV or placebo daily for 20 weeks. At MGH only, 12 individuals (4 from each of the two EFV groups and placebo) will participate in the unique "heavy water" SILK protocol assessing the kinetics of deuterium enrichment in plasma 24-hydroxycholesterol (24-OHC). All study participants at both sites will have their blood, cerebral spinal fluid, and urine analyzed at various points throughout the study. All participants will have their DNA genotyped for APOE isoforms (E2, E3 or E4) and single nucleotide polymorphisms (SNPs) in CYP46A1 (rs754203) and CYP2B6 (rs3745274) to be used for post-hoc analysis.
For unknown reasons, this neuron-specific enzyme becomes specifically expressed in astrocytes of AD patients; plasma levels of 24-OHC, the product of CYP46A1, also change in AD patients-there are slight elevations of plasma levels in the early stages of AD, followed by decreases in the later stages of AD, (the elevations have been interpreted to represent demyelination of the brain and subsequent release of 24-OHC into the systemic circulation, and the decreases could be attributed to loss of CYP46A1 during the physical process of neuronal degeneration); and, finally, CYP46A1 is highly polymorphic enzyme with the most frequent intronic SNPs (rs754203, rs3742376, rs7157609, and rs4900442 being found at ~29- 40% frequency in the population.
Description: Changes in plasma 24-hydroxycholesterol (measured in ng/dL) by more or equal to 30%.Measure: Plasma levels of 24-hydroxycholesterol Time: 1 year
Description: Plasma appearance of deuterated 24-hydroxycholetserol (measured in ng/dL) will be measured within 14 days after a participant will drink the last portion of deuterated water in the Stable Isotope Kinetics Labeling Study.Measure: Plasma levels of deuterated 24-hydroxycholesterol Time: 1 year
Description: Participants will be genotyped for the APOE isoform status (E2, E3, or E4) and presence of the SNPs rs754203 and rs3745274 in CYP46A1 and CYP2B6, respectivelyMeasure: APOE isoform status (E2, E3, or E4) and presence of the SNPs rs754203 and rs3745274 in CYP46A1 and CYP2B6, respectively. Time: 1 year