Cascadian Therapeutics Announces Presentation of Tucatinib in Combination Therapy in Patients with Cutaneous HER2+ Metastatic Breast Cancer

SEATTLE, Oct. 10, 2016 (GLOBE NEWSWIRE) -- Cascadian Therapeutics (NASDAQ:CASC), a clinical-stage biopharmaceutical company, today announced the presentation of clinical activity of tucatinib, its investigational, highly selective small molecule HER2 inhibitor, in combination therapy at the European Society for Medical Oncology (ESMO) 2016 Congress being held October 7-11, 2016 in Copenhagen, Denmark.
Data from the poster presentation (#278 “Cutaneous Responses in HER2+ Metastatic Breast Cancer in Phase 1b Study of Tucatinib (ONT-380), an Oral HER2-Specific Inhibitor in Combination with Capecitabine and/or Trastuzumab in Third Line or Later Treatment”), reported on responses of skin lesions in HER2+ metastatic breast cancer patients following treatment with tucatinib in combination with capecitabine and/or trastuzumab.

“Data suggest that skin may be a sanctuary site for metastatic breast cancer similar to the brain and therefore poorly penetrated by drug therapies that could help control cancer,” commented Dr. Alison Conlin, study author and Medical Oncologist at Providence Cancer Center, Portland, OR. “As a result, any meaningful improvement in patients' skin metastases would be a welcome development, particularly given the morbidity that these skin metastases cause. Tucatinib, when used in combination, appears to show early evidence of activity in treating cutaneous HER2+ metastases, a common yet difficult-to-treat aspect of this disease.”

Summary of Results
Dr. Conlin reported on eight patients with HER2+ metastases to the skin who received the maximum tolerated tucatinib dose in combination with capecitabine and/or trastuzumab from the Company’s Phase 1b combination study. All patients in this study had previously been treated with trastuzumab, a taxane, and T-DM1. Most patients had also received lapatinib, pertuzumab, and/or radiotherapy to the skin. Patients had previously received a median of six lines of drug therapy.

Overall systemic clinical responses reported in this patient population included one complete response, three partial responses and four with stable disease. Responses observed in skin lesions in these patients included one complete response, four partial responses and three patients with stable disease, including one partial response of a patient receiving tucatinib and trastuzumab only.1 Tucatinib was previously reported to be well tolerated by patients in the Phase 1b combination studies, with a manageable adverse event profile.

“We’re pleased to see continued evidence of systemic clinical activity with tucatinib in combination therapy, including in patients with difficult-to-treat metastases such as these,” commented Luke N. Walker, MD, Vice President, Clinical Development, Cascadian Therapeutics. “This potential benefit of tucatinib for patients with skin metastases is an interesting finding that we will continue to monitor.”

A copy of the poster can be found in the Clinical Data and Scientific Publications section of the Company’s website at

1 Partial responses in the skin were defined as a greater than 30 percent reduction in the sum of diameters of all target skin lesions from baseline while a complete response was defined as a disappearance of all skin lesions.

About Cascadian Therapeutics
Cascadian Therapeutics is a clinical-stage biopharmaceutical company dedicated to developing innovative product candidates for the treatment of cancer. Our lead product candidate, tucatinib, also known as ONT-380, is an orally active and selective small molecule HER2 inhibitor, which has been studied in approximately 200 patients to date. Preliminary results from two ongoing Phase 1b studies of tucatinib in combination showed promising systemic activity, a favorable safety profile and encouraging activity against brain metastases. Cascadian Therapeutics is also conducting a randomized, double-blind, placebo-controlled Phase 2 study called HER2CLIMB. The study is evaluating tucatinib versus placebo in combination with capecitabine and trastuzumab in late stage HER2+ breast cancer patients, with and without brain metastases, who have previously been treated with a taxane, trastuzumab, pertuzumab and T-DM1. This study is expected to enroll 180 patients across approximately 100 clinical sites in the U.S., Canada, and Western Europe. For more information, visit The Company is also developing a cell cycle inhibitor, Chk1, and plans to move the program forward through IND-enabling studies in 2017. For more information, visit

Forward-Looking Statements
In order to provide Cascadian Therapeutics' investors with an understanding of its current results and future prospects, this release contains statements that are forward-looking. Any statements contained in this press release that are not statements of historical fact may be deemed to be forward-looking statements. Words such as "believes," "anticipates," "plans," "expects," "will," "intends," "potential," "possible" and similar expressions are intended to identify forward-looking statements. These forward-looking statements include Cascadian Therapeutics' expectations regarding the proposed reverse stock split, reduction in authorized capital and special meeting.

Forward-looking statements involve risks and uncertainties related to Cascadian Therapeutics' business and the general economic environment, many of which are beyond its control. These risks, uncertainties and other factors could cause Cascadian Therapeutics' actual results to differ materially from those projected in forward-looking statements, including the risks associated with the costs and expenses of developing its product candidates, the adequacy of financing and cash, cash equivalents and investments, changes in general accounting policies, general economic factors, achievement of the results it anticipates from its preclinical development and clinical trials of its product candidates and its ability to adequately obtain and protect its intellectual property rights. Although Cascadian Therapeutics believes that the forward-looking statements contained herein are reasonable, it can give no assurance that its expectations are correct. All forward-looking statements are expressly qualified in their entirety by this cautionary statement. For a detailed description of Cascadian Therapeutics' risks and uncertainties, you are encouraged to review the documents filed with the securities regulators in the United States on EDGAR and in Canada on SEDAR. Except as required by law, Cascadian Therapeutics does not undertake any obligation to publicly update its forward-looking statements based on events or circumstances after the date hereof.

Investor Contact: Julie Rathbun Rathbun Communications 206-769-9219 Naomi Eichenbaum The Trout Group 646-378-2968 Media Contact: Brad Miles BMC Communications 917-570-7340

Source:Cascadian Therapeutics