April 17, 2020
The U.S. FDA has approved Tukysa™ (tukatinab) tablets, manufactured by Seattle Genetics, to treat adult patients who have advanced forms of HER2-positive breast cancer that is inoperable or has spread to other parts of the body, including the brain, and who have received one or more prior treatments.
Approximately 279,100 new cases of breast cancer are expected to be diagnosed in the U.S. in 2020, and up to 20% of these cases may be HER2-positive. HER2 is a protein also called human epidermal growth factor receptor 2 that drives the growth of cancer cells. HER2-positive breast cancer tends to be aggressive and have a higher rate of occurrence than HER2-negative breast cancer. It is also associated with spread of cancer into the brain. Up to half of patients with HER2-positive breast cancer will develop brain metastases over time.
In a clinical trial, patients treated with Tukysa, trastuzumab, and capecitabine had a median progression-free survival (PFS) of 7.8 months compared to 5.6 months in patients who received placebo with trastuzumab and capecitabine. For patients who had brain metastases, the median PFS with Tukysa, trastuzumab, and capecitabine was 7.6 months compared to 5.4 months in patients who received placebo, trastuzumab, and capecitabine.
Recommended dosing is 300mg of Tukysa taken by mouth twice a day with or without food. For patients who have severe hepatic impairment, the dosage should be reduced to 200mg twice a day.
Tukysa is available at a wholesale acquisition cost (WAC) of $18,500 for a 120-count of 150mg tablets.