Cascadian Therapeutics Announces FDA Orphan Drug Designation Granted to Tucatinib for the Treatment of HER2+ Metastatic Colorectal Cancer

On September 27, 2017 Cascadian Therapeutics, Inc. (NASDAQ:CASC), a clinical-stage biopharmaceutical company, reported that the U.S. Food and Drug Administration (“FDA”) has granted orphan drug designation to tucatinib for the treatment of HER2-positive (HER2+) metastatic colorectal cancer (Press release, Cascadian Therapeutics, SEP 27, 2017, View Source [SID1234520657]). Tucatinib is an investigational oral, small molecule kinase inhibitor that is highly selective for HER2 and is the Company’s lead product in development.

The FDA’s Orphan Drug Designation program provides orphan status to drugs defined as those intended for the safe and effective treatment, diagnosis or prevention of rare diseases that affect fewer than 200,000 people in the United States. Orphan designation qualifies the sponsor of the drug for certain development incentives, including tax credits for qualified clinical testing, prescription drug user fee exemption and 7-year marketing exclusivity upon FDA approval.

“We are pleased to receive FDA orphan drug designation for tucatinib in HER2+ metastatic colorectal cancer, our second orphan designation in addition to breast cancer with brain metastases,” said Scott Myers, President and CEO of Cascadian Therapeutics. “We believe tucatinib has the potential to address unmet medical needs of patients in a broad range of HER2-positive cancers. We are currently supporting an investigator-initiated study evaluating tucatinib for the treatment of patients with HER2+ metastatic colorectal cancer.”

“We are conducting a Phase 2 study called MOUNTAINEER evaluating tucatinib in combination with trastuzumab for patients with HER2 amplified metastatic colorectal cancer,” said John Strickler, MD, Assistant Professor of Medicine, Division of Medical Oncology, Duke University Medical Center, and principal investigator of the MOUNTAINEER study. “There remains an unmet clinical need for new treatments for patients with HER2 amplified metastatic colorectal cancer. Tucatinib is a potent and selective inhibitor of HER2 in vitro, and is active in non-clinical HER2+ colorectal tumor models. Based on these data, we believe tucatinib has the potential to be a new therapeutic option for these patients.”

The study, known as MOUNTAINEER, is currently recruiting participants. Additional details about MOUNTAINEER can be found at www.clinicaltrials.gov (NCT03043313).

The American Cancer Society estimates 135,430 new cases of colorectal cancer will be diagnosed in the U.S. in 2017, and expects colorectal cancer to cause over 50,000 deaths in 2017. Colorectal cancer is the third leading cause of cancer death in both men and women in the U.S. While the prevalence of HER2 amplified colorectal cancer varies depending on study methods and population, approximately 3-to-8 percent of these patients would be expected to potentially benefit from HER2-targeted therapy.1

About Tucatinib

Tucatinib is an investigational, orally bioavailable, potent tyrosine kinase inhibitor that is highly selective for HER2 without inhibition of EGFR. Inhibition of EGFR has been associated with clinical toxicities, including skin rash and diarrhea. Tucatinib has shown activity as a single agent and in combination with both chemotherapy and other HER2 directed agents such as trastuzumab.2,3 Studies of tucatinib in these combinations have shown activity both systemically and in brain metastases. HER2 is a growth factor receptor that is overexpressed in multiple cancers, including breast, ovarian and gastric cancers. HER2 mediates cell growth, differentiation and survival. Tumors that overexpress HER2 (HER2+) are more aggressive and historically have been associated with poor overall survival, compared with HER2-negative cancers.