Array BioPharma Announces Positive Results for HER2 Inhibitor, ARRY-380, in Breast Cancer Patients

Array BioPharma Inc. ARRY today announced positive interim results of its novel, oral HER2 (ErbB2) inhibitor, ARRY-380, in a Phase 1 trial in patients with advanced cancer. These results are being presented at the 2010 ASCO Breast Cancer Symposium in National Harbor, Maryland. The complete poster (#A7) entitled, “A Phase 1 Study to Assess the Safety, Tolerability and Pharmacokinetics of ARRY-380 - an Oral Inhibitor of HER2,” is available as a PDF on Array's website: http://www.arraybiopharma.com/PatentsPublications/Default.asp?PBCategoryID=3. Interim results were presented on 17 HER2 positive metastatic breast cancer patients treated with ARRY-380 at doses greater than or equal to 200 mg BID. All of these patients had been previously treated with Herceptin® (trastuzumab), and 81 percent were previously treated with Tykerb® (lapatinib). Twenty-nine percent of these patients had a partial response or stable disease for six months or longer. Thirteen of the 17 patients had measurable disease as defined by the Response Evaluation Criteria in Solid Tumors (RECIST); of these patients, seven (54 percent) had regressions in target lesions. Of the four patients with no measurable disease, three had regressions of non-target chest wall lesions as documented by photographic evaluation. ARRY-380 has been well-tolerated; the predominant treatment-related adverse events have been Grade 1. Because ARRY-380 is selective for HER2 and does not inhibit EGFR, there was, as expected, a low incidence and severity of diarrhea, rash and fatigue. Additionally, there were no Grade 4 events or adverse cardiac events reported. The maximum tolerated dose of ARRY-380 established in this Phase 1 trial is 600 mg (twice daily). An expansion cohort in patients with HER2 positive metastatic breast cancer is ongoing to confirm safety and explore efficacy and pharmacodynamic markers. “I am optimistic about this orally available, selective HER2 inhibitor, ARRY-380. To date, it has been well-tolerated and has shown activity in patients previously treated with trastuzumab and lapatinib,” said Stacy Moulder, M.D., Clinical Investigator, M.D. Anderson Cancer Center. “We remain enthusiastic about prospects for the drug based on this new data.” “Maintaining tumor remission while improving breast cancer patients' quality of life represents one of the largest commercial opportunities in cancer therapy,” said Kevin Koch, Ph.D., President and Chief Scientific Officer. “In this clinical trial, ARRY-380 has been well-tolerated and has shown signs of clinical activity, including the shrinking of visceral metastases.”