Tykerb shows promise with CNS Tumors

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Research data from N.U. Lin and colleagues update understanding of breast cancer.

Pain & Central Nervous System Week - Jun. 02, 20082008 JUN 2 - (NewsRx.com) -- " One third of women with advanced human epidermal growth factor receptor 2 (HER-2)-positive breast cancer develop brain metastases; a subset progress in the CNS despite standard approaches (see also Breast Cancer). Medical therapies for refractory brain metastases are neither well-studied nor established," scientists in the United States report.

"We evaluated the safety and efficacy of lapatinib, an oral inhibitor of epidermal growth factor receptor (EGFR) and HER-2, in patients with HER-2-positive brain metastases. Patients and Methods Patients had HER-2-positive breast cancer, progressive brain metastases, prior trastuzumab treatment, and at least one measurable metastatic brain lesion. Patients received lapatinib 750 mg orally twice a day. Tumor response was assessed by magnetic resonance imaging every 8 weeks. The primary end point was objective response (complete response [CR] plus partial response [PR]) in the CNS by Response Evaluation Criteria in Solid Tumors (RECIST). Secondary end points included objective response in non-CNS sites, time to progression, overall survival, and toxicity. Thirty-nine patients were enrolled. All patients had developed brain metastases while receiving trastuzumab; 37 had progressed after prior radiation. One patient achieved a PR in the brain by RECIST (objective response rate 2.6%, 95% conditional CI, 0.21% to 26%). Seven patients (18%) were progression free in both CNS and non-CNS sites at 16 weeks. Exploratory analyses identified additional patients with some degree of volumetric reduction in brain tumor burden. The most common adverse events (AEs) were diarrhea (grade 3, 21%) and fatigue (grade 3, 15%). The study did not meet the predefined criteria for antitumor activity in highly refractory patients with HER-2-positive brain metastases," wrote N.U. Lin and colleagues.

The researchers concluded: "Because of the volumetric changes observed in our exploratory analysis, further studies are underway utilizing volumetric changes as a primary end point."

Lin and colleagues published their study in the Journal of Clinical Oncology (Phase II trial of lapatinib for brain metastases in patients with human epidermal growth factor receptor 2-positive breast cancer. Journal of Clinical Oncology, 2008;26(12):1993-1999)
For more information, contact E.P. Winer, Dana Farber Cancer Institute, 44 Binney St., Boston, MA 02115, USA
Publisher contact information for the Journal of Clinical Oncology is: American Society Clinical Oncology, 330 John Carlyle St., Ste. 300, Alexandria, VA 22314, USA.