The fourth imaging agent will be 99mTc-EC-metronidazole
("99mTc-EC-MN") which will be studied as a cellular hypoxia targeting agent
for oncology and as a functional imaging agent to assess cardiovascular and
neurological disease. The company is planning to submit an IND application to
the FDA in the third or early fourth quarter 2005 to start a Phase I
clinical trial. The company believes that 99mTc-EC-MN will be effective in measuring tumor
hypoxia and thus will provide the medical oncologist with useful and important
information on selection of therapy. Whether a tunor is hypoxic is important in
the decision to give the patient external radiation treatment. The company is also considering an IND application
to conduct a study in cardiology. This will be determined
in the Fall of 2005. (Please see image below of patient with
esophageal cancer who was imaged with 99m
Tc-EC-MN).
Another example of how 99mTc-EC-MN
can be used is in neurology. A collaborative study conducted in South Korea on
patients who had suffered ischemic stroke to the brain evaluated the
relationship between neurological outcome and uptake of 99mTc-EC-MN
in peri-infarcted regions of the brain. 99mTc-EC-MN
was used to identify hypoxic (absence of oxygen) tissue within the affected area
of the brain. When
used in conjunction with 99mTc-ECD, a blood flow perfusion agent,
99mTc-EC-MN was found to be useful in predicting neurological outcome
in patients within the first 48 hours following ischemic stroke, thus giving the
neurologist important information on whether the patient may have salvageable
tissue and thus benefit from tissue rescue therapy. The results of the
99mTc-EC-MN study was recently published in the cardiology journal
Stroke. 34(4):982-986,2003.
The above images are of two patients who
have suffered infarct damage to the right side of the brain. Slide #1 for each patient
is an MRI image which shows the area effected. Slide #2 shows the infarct
area using 99m Tc labeled ECD, a perfusion agent. Slide #3
shows the area of the brain (outlined in yellow) that indicates hypoxic tissue
within the impacted region. The potentially viable tissue is illuminated using
99mTc labeled metronidazole.
This information is useful to the neurologist in deference to
making a decision regarding further surgical intervention for the
patient.
.
r & d
