Shares of cancer drug maker Seattle Genetics soared more than 17 percent Monday morning following positive results for a new drug that fights aggressive breast cancers.
Tucatinib is a daily pill that targets human epidermal growth factor receptor 2, or HER2, a protein that promotes the growth of cancer cells and is found in around 20 percent of breast cancers.
The Phase 3 trial showed that tucatinib delivered better results in combination with two other cancer drugs — Roche’s Herceptin (trastuzumab) and chemotherapy drug capecitabine — than those drugs alone. Overall, tucatinib reduced the risk of cancer advancement by 46 percent and the risk of death by 34 percent.
At the start of the trial, nearly half of the 600 patients also had the cancer in their brains, which occurs in around 30 to 50 percent of patients with HER2-positive breast cancer. Tucatinib reduced the risk of disease progression or death in those patients by 52 percent compared with the two other drugs alone.
“The addition of tucatinib to the commonly used doublet of trastuzumab and capecitabine represents a potential significant clinical advance for patients with metastatic HER2-positive breast cancer, importantly, including those with brain metastases,” Dr. Roger Dansey, chief medical officer at Seattle Genetics, said in a statement. “Based on these findings, we plan to unblind the trial and offer tucatinib to patients on the control arm.”
Based on the results, the company is planning to submit a new drug application in the first quarter of next year.
Tucatinib was originally developed by Cascadian Therapeutics, which sold to Seattle Genetics for $614 million at the start of 2018. If approved, SVB Leerink analyst Andy Berens thinks the drug could bring in $420 million in annual sales, Stat News reported.
There are a number of drugs on the market that target HER2-positive breast cancer, including Roche’s Herceptin, Perjeta, and Kadcyla. AstraZeneca and Daiichi Sankyo are also working together on a therapy that targets breast cancers that express HER2.
Seattle Genetics’ stock is up 76 percent since the start of the year. In April, CEO and co-founder Clay Siegall got a 110 percent raise with an $18.1 million pay package.
Earlier this year, the company raised $575 million in a stock offering to expand the sales of lymphoma cancer drug Adcetris and to develop enfortumab vedotin, a drug for metastatic urothelial cancer.