Researchers at Massachusetts General Hospital and Harvard Medical School also said that the imaging and biomarker studies they performed as treatment was underway have revealed why the treatment, AZD2171, ultimately failed, and what might improve the response.
The blood biomarker studies showed that as tumors stopped relying on vascular endothelial growth factors (VEGF) to pump up blood flow to them, and VEGF is what AZD2171 targets, they started using two other growth factors. Neither of the two had previously been recognized as important for human tumor blood vessel growth.
The study is unique because it is the first to test AZD2171 in glioblastoma patients, and to find that it “offered promising benefits such as tumor shrinkage and reduction of brain swelling,” said Tracy Batchelor, chief of neuro-oncology at Massachusetts General Hospital.
Of the patients who participated, more than half experienced tumor shrinkage of 50% or more. The agent also reduced edema, or swelling, in the brain. Because of that, some patients were able to stop using steroids, which can cause debilitating side effects.
“We all recognize that what we need to do now is combine this therapy with other types of treatments, either existing or to be developed, and to deliver these drug combinations during the window we have identified,” Dr Batchelor said. “This might help us manage patients much more effectively.”