Bridging Study of C11 PiB and F18 Flutemetamol Brain PET

Alzheimer's Disease Clinical Trial

Official title: Bridging Study of C11 PiB and F18 Flutemetamol Brain PET

Status Completed

Clinical Trial Summary

The intent of this research protocol is to test the equivalency of two amyloid imaging drugs (C11 Pittsburgh Compound B and F18 Flutemetamol). The investigators hypothesize that there will be no significant difference in the distribution of the agents to areas of amyloid deposition in the brain or to other normal brain structures. Recent data have shown similarity in the distribution of the drugs in subjects with AD or mild cognitive impairment (MCI). No comparison data of the two PET drugs in normal subjects has been published. It is important to understand differences in the images and biodistribution from the two drugs in normal subjects as nonspecific accumulation of the drugs in brain structures such as white matter appear to differ slightly and could affect image performance.

The current clinical functional imaging standard for patients with indeterminate cognitive impairment is FDG PET. To allow a comparison of the PET amyloid imaging compounds with FDG PET, FDG PET scans will also be important to acquire in the subjects for comparison.

Clinical Trial Description

The specific aims of this research proposal are outlined below.

1. Compare C11 PiB and F18 Flutemetamol in the same subjects to determine their diagnostic accuracy in AD and normal subjects.

We have conduced 800 C11 PiB PET scans in subjects at Mayo. Only one of these subjects was imaged with both C11 PiB and an F18 amyloid imaging agent (AV-138). Subtle differences are noted in the intensity of accumulation possibly due to the isotope differences as can be seen in the figure below (Figure 1). These data are not sufficient to understand the different characteristics or determine equivalent accuracy of the C11 and F18 drugs. We therefore propose acquiring sufficient data to help characterize the two drugs. We will scan both AD and normal subjects to allow us to understand the diagnostic accuracy of the two drugs.

2. Determine the relative differences in biodistribution of the PET agents and what corrections could be made to allow for adjustments of the data obtained using C11 PiB that will allow accurate comparisons with F18 Flutemetamol data in the same subjects.

If biodistribution differences in the two drugs are found, we will attempt to estimate quantitative correction factors in the C11 images to help to data obtained from the scans be comparable to future serial F18 Flutemetamol data.

3. Acquire FDG PET in the subjects to compare FDG PET imaging to PiB imaging. ;

Study Design

Allocation: Non-Randomized, Intervention Model: Parallel Assignment, Masking: Open Label, Primary Purpose: Basic Science

Related Conditions & MeSH terms

• Alzheimer Disease
• Alzheimer's Disease

• NCT number: NCT01607476
• Study type: Interventional
• Source: Mayo Clinic
• Status: Completed
• Phase: Phase 2
• Start date: July 2012
• Completion date: March 2016