When NCI's new Molecular Imaging Clinic opens in January 2009, it will be one of the few places in the world where state-of-the-art imaging tools are dedicated to understanding how drugs behave in people with cancer. What is learned there could help investigators determine how best to use existing drugs and determine the properties of new molecularly targeted drugs that are just entering the clinic.
"Our goal is to use advanced imaging technologies to accelerate the development of therapies for cancer," said Dr. Peter Choyke, who directs the Molecular Imaging Program in NCI's Center for Cancer Research (CCR). He has assembled a multidisciplinary team that includes imaging scientists, chemists, physicists, engineers, oncologists, and molecular biologists. They have many collaborators inside and outside NCI.
The clinic was created in part because the existing imaging tools in the NIH Clinical Center were needed for patient studies, leaving little time for translational research. As molecularly targeted therapies were emerging several years ago, NCI officials saw the potential importance of imaging studies in drug development.
"Imaging can answer three important questions," said Dr. Choyke. "Does a patient have the target of a particular drug? Does the drug hit the target? And if so, does it do anything helpful for the patient?" When imaging shows that a drug has not reached its destination, researchers can modify the drug or its delivery. Or, they can abandon the project and redirect precious resources elsewhere.
The new facility has undergone extensive renovation and will have the latest scanners for detecting cancer and tracking drugs in the body, including a PET/CT unit, which can simultaneously capture PET and CT images, and 3 Tesla whole-body MRI.
Imaging studies are underway to study the behavior of drugs such as trastuzumab (Herceptin). Experimental imaging agents also will be tested in phase 0 trials - small studies in which patients receive a very low dose of an experimental drug to determine whether it behaves in people as it does in animal or cell models.
Many studies will be partnerships with investigators at NCI, other institutions, pharmaceutical companies, and the imaging-equipment industry. NCI's Division of Cancer Treatment and Diagnosis played an integral role in the clinic's development and provides critical materials such as radioactive substances that are attached to drugs.
Radiolabeled drugs are given at low doses so they do not result in physiologic effects, but they still go to the same places in the body as drugs given at therapeutic doses. Investigators may eventually make "go" or "no-go" decisions about new drugs based in part on whether they hit their target and whether they have off-target (side) effects.
"Our mission is to use the cameras to do translational studies that will make drug development faster," said Dr. Karen Kurdziel, who directs the new clinic. "There are very few imaging centers dedicated to drug discovery and research. We have an incredible opportunity here."