Product Profile and Unmet Medical Need
Tukysa (tucatinib) is an oral tyrosine kinase inhibitor of the HER2 protein, approved in 36 countries. Currently, no HER2-directed therapies for colorectal cancer are approved by the FDA.
Pivotal Phase 2 Trial Announcement
Recently, Seagen announced positive top-line results from a pivotal Phase 2 clinical trial evaluating Tukysa (tucatinib) in combination with the anti-HER2 monoclonal antibody trastuzumab in patients with HER2-positive metastatic colorectal cancer (mCRC) who have received prior treatment. These data will form the basis for the company’s planned supplemental New Drug Application (sNDA) submission to the U.S. Food and Drug Administration (FDA) under the FDA’s accelerated approval program.
Core Efficacy Outcomes
Pivotal Phase 2 trial results showed a confirmed objective response rate (cORR) of 38.1% [95% confidence interval (CI): 27.7, 49.3] by blinded independent central review (BICR). The median duration of response (DoR) by BICR was 12.4 months [95% CI: 8.5, 20.5].
Safety Profile
The combination of tucatinib and trastuzumab was generally well tolerated. The most common (≥20%) treatment-emergent adverse events were diarrhea, fatigue, nausea, and infusion-related reactions, which were predominantly low-grade.
Executive Quote
“There is a clear unmet need for new therapies in patients with HER2-positive metastatic colorectal cancer,” said Dr. Roger Dansey, Interim Chief Executive Officer and Chief Medical Officer of Seagen. “We are excited by the potential of this tucatinib combination to deliver meaningful antitumor activity for patients through durable responses and a tolerable safety profile. Based on the strength of these data, we plan to hold regulatory discussions with the FDA with the goal of submitting a supplemental New Drug Application for TUKYSA.”
Data Presentation
Full data from the pivotal Phase 2 trial will be presented by Dr. John H. Strickler of Duke University Medical Center at the European Society for Medical Oncology (ESMO) World Congress on Gastrointestinal Cancer, held in Barcelona, Spain from June 29 to July 2, 2022.
Prior FDA Approval
Previously, in April 2020, the FDA approved TUKYSA in combination with trastuzumab and capecitabine for the treatment of adult patients with advanced unresectable or metastatic HER2-positive breast cancer, including patients with brain metastases, who have received one or more prior anti-HER2-based regimens in the metastatic setting.
