CHICAGO—The novel biologic agent ZD1839 (gefitinib; Iressa) provided some clinical benefit, and may have relieved bone pain, in heavily pretreated patients with advanced breast cancer, according to results of a recent phase II trial. Of 63 patients treated, 9 or 14.3% had a partial response or stable disease, and 15% of patients remained on treatment for 4 to 8 months or longer
Some patients remained on therapy, even as disease progressed, because they had marked relief of bone pain, said investigator Kathy S. Albain, MD, professor of medicine at Loyola University Medical Center in Chicago. "A not insignificant subset of patients may have achieved benefit…and additional patients had major relief of bone pain, despite objective progression," said Dr. Albain.
Early Clinical Data
The findings presented by Dr. Albain represent some of the first clinical data for ZD1839 in breast cancer. ZD1839 is an inhibitor of epidermal growth factor receptor tyrosine kinase (EGFR-TK), a key modulator of tumor cell function. ZD1839 has already attracted considerable attention in the scientific community and popular media for investigations in solid tumors, most notably non-small-cell lung cancer.
In this multicenter study, 1839IL/0156, women with metastatic breast cancer (median age 52 years) received ZD1839 at 500 mg/day until disease progression or withdrawal due to toxicity. Twenty-seven women (43%) were hormone receptor-positive and 50 (79%) had visceral disease.
Most of the women (49 patients, or 78%) had at least two prior chemotherapy regimens for metastatic disease, while 34 (54%) had one or more prior hormonal therapies. About one-third had received trastuzumab(Drug information on trastuzumab) (Herceptin). In addition, most patients also had prior adjuvant chemotherapy with or without hormonal therapy.
Generally Well Tolerated
