Medical imaging takes key role in revolutionary new cancer protocol

March 26, 2010
Greg Freiherr

Imaging will play a pivotal role in a clinical trial that promises to change the way medical research is done, not only in oncology, but throughout medicine.

Imaging will play a pivotal role in a clinical trial that promises to change the way medical research is done, not only in oncology, but throughout medicine.

A multicenter trial, begun last week at the University of California, San Francisco and slated to expand to about 20 cancer centers in the U.S., will use medical images to assess patient response to experimental drugs being tested against breast cancer. The cancer trial will gauge how well drugs work in patients before their tumors have been surgically removed so that the effect of the drug can be quantified with medical imaging.

“By measuring tumor volume with imaging and validating that with pathological response, we will learn more about the use of images as a marker for drug effects,” said Dr. Janet Woodcock, director of the FDA Center for Drug Evaluation and Research.

Radiologists have known for years that tumor volume can indicate patient response to therapy. Until now, however, it has not been a central component in a major research design.

Investigators hope that imaging and other data obtained early in the testing of this trial, dubbed I-SPY2 (Investigation of Serial studies to Predict Your therapeutic response), will guide decisions about which treatments hold the greatest promise for success, just as genetic and biological markers drawn from the tumors of patients participating in the trial will be used to identify who will be most likely to respond to specific drugs being tested. This “adaptive design” promises to affect breast cancer patients immediately. But its success would have much broader implications.

“This is not just an important trial for breast cancer,” Woodcock said. “It is a model for innovation in drug development-something that is seriously needed.”

Drug companies currently spend more than $1 billion and 12 to 15 years to develop a single drug, which ultimately is tested on thousands of patient volunteers before entering the U.S. market. If the design of this trial works, it will dramatically reduce the number of subjects, while shaving years and hundreds of millions of dollars off the testing process.

In this new research paradigm, dozens, or at most a few hundred, patients will be tested in phase II trials, allowing researchers to home in on the specific type of patients, if any, who respond to treatment. Extended trials then will be more likely to succeed. And if they do not, drug developers can move on to other candidates, conserving effort and funds, and speeding the most promising drugs to phase III tests and, hopefully, into commercial production.

If this happens, I-SPY2 will have changed the way clinical trials are conducted, serving as a model for research aimed at questions in and outside of oncology. In the process, medical imaging will have been established as a core technology, critically important to the early assessment of therapeutic candidates and an integral part of patient assessment and monitoring when those therapies enter routine clinical use.