News | July 24, 2012

Head-to-Head Study Compares Navidea’s AZD4694 to the Gold Standard for Imaging Beta Amyloid Protein

Trial examines AZD4694 performance characteristics and blinded reader confidence when used as an aid in diagnosing Alzheimer's Disease

July 24, 2012 — Navidea Biopharmaceuticals Inc., a specialty pharmaceutical company focused on precision diagnostic radiopharmaceuticals, announced that clinical data from a head-to head study comparing its amyloid imaging candidate, AZD4694, to the benchmark amyloid imaging agent, 11C-PiB (PiB), was presented at the Alzheimer's Association International Conference (AAIC) in Vancouver, Canada by Professor Christopher Rowe, MD, FRACP, Director of the Department of Nuclear Medicine and Centre for PET at Austin Health, Melbourne, Australia.

In addition, on Friday, July 13, 2012, Navidea received approval for its Phase 2 AZD4694 protocol from the New England Institutional Review Board (IRB), a centralized IRB that oversees the approval of clinical protocols for investigational drugs for multiple research organizations. Trial enrollment is expected to commence in the coming months.

Rowe’s talk was entitled, “Head to head comparison of 11C-PiB and 18F-AZD4694 for A? imaging in ageing and dementia.” The presentation highlighted new results from a blinded-reader analysis which examined imaging characteristics such as binding kinetics, standard uptake value ratios (SUVR) in three time intervals, and non-specific white-matter retention for these agents obtained in the same subjects. The two agents, 11C-PiB and 18F-AZD4694, were employed to sequentially image the brains of forty-five participants (25 healthy elderly controls, 10 subjects with Mild Cognitive Impairment, 7 subjects with probable Alzheimer’s Disease and 3 subjects with fronto-temporal dementia). The mean age of the participant groups was about 74, except that the three fronto-temporal dementia patients averaged about 68 years old. Cognitive impairments in the patient groups showed mean scores on the Mini-Mental State Examination of 24 to 27 and were within the mild to moderate range.

As previously reported, quantitative measures, such as SUVR, of 18F-AZD4694 binding to cortical amyloid plaques are essentially identical to 11C-PiB. A very tight performance correlation was observed (r=0.98, p<0.0001; slope 0.95). Visually, images obtained in the same patient with the same scan times, the same data processing and the same display scales, were identical. 18F-AZD4694 had comparable binding kinetics and dynamic range of SUVR to the benchmark 11C-PiB as well as similar high values of cortex to white matter ratios. Using the PiB as reference, the sensitivity, specificity, and overall accuracy within the 40 to 60 minute readings ranged from 94 percent to 98 percent. Additionally, confidence levels from the blinded readers averaged 93 percent using 40 to 60 minute readings, indicating a high degree of confidence in the interpretability of the images within this time range.

Related Content

Transpara Deep Learning Software Matches Experienced Radiologists in Mammogram Reading
News | Computer-Aided Detection Software | January 12, 2018
Deep learning and artificial intelligence improves the efficiency and accuracy of reading mammograms, according to...
Smartphone Addiction Creates Imbalance in Brain
News | Mobile Devices | January 11, 2018
Researchers have found an imbalance in the brain chemistry of young people addicted to smartphones and the internet,...
Fat Distribution in Women and Men Provides Clues to Heart Attack Risk
News | Women's Health | January 11, 2018
January 11, 2018 – It’s not the amount of fat in your body but where it is stored that may increase your risk for hea
Minimally Invasive Treatment Provides Relief from Back Pain

Lumbar spine MRI showing disc herniation and nerve root at baseline and one month after treatment

News | Interventional Radiology | January 11, 2018
The majority of patients were pain free after receiving a new image-guided pulsed radiofrequency treatment for low back...
Emergency Radiologists See Inner Toll of Opioid Use Disorders

Rates of Imaging Positivity for IV-SUDs Complications. Image courtesy of Efren J. Flores, M.D.

News | Clinical Study | January 11, 2018
January 11, 2018 – Emergency radiologists are seeing a high prevalence of patients with complications related to opio
CT Shows Enlarged Aortas in Former Pro Football Players

3-D rendering from a cardiac CT dataset demonstrating mild dilation of the ascending aorta.

News | Computed Tomography (CT) | January 11, 2018
Former National Football League (NFL) players are more likely to have enlarged aortas, a condition that may put them at...
Study Finds No Evidence that Gadolinium Causes Neurologic Harm

MR images through, A, C, E, basal ganglia and, B, D, F, posterior fossa at level of dentate nucleus. Images are shown for, A, B, control group patient 4, and the, C, D, first and, E, F, last examinations performed in contrast group patient 13. Regions of interest used in quantification of signal intensity are shown as dashed lines for globus pallidus (green), thalamus (blue), dentate nucleus (yellow), and pons (red).

News | Contrast Media | January 11, 2018
January 11, 2018 — There is no evidence that accumulation in the brain of the element gadolinium speeds cognitive dec

Size comparison between 3-D printed prosthesis implant and a penny.

News | 3-D Printing | January 11, 2018
January 11, 2018 — Researchers using...
RSNA 2017 technical exhibits, expo floor, showing new radiology technology advances.
Feature | RSNA 2017 | January 11, 2018
January 11, 2018 — Here is a list of some of the key clinical study presentations, articles on trends and videos from
Hip Steroid Injections Associated with Bone Changes

58-year-old woman with left hip pain. X-ray from one month prior to the steroid/anesthetic injection demonstrates moderate joint space narrowing (arrows) and bony proliferation (arrowheads).

News | Orthopedic Imaging | January 11, 2018
January 11, 2018 – Osteoarthritis patients who received a steroid injection in the hip had a significantly greater in
Overlay Init