The US Food and Drug Administration (FDA) this morning announced the approval of Kadcyla (ado-trastuzumab emtansine), a new breast cancer therapy for patient with HER2-positive, metastatic breast cancer that did not respond to prior treatment.
The 22 February 2013 announcement by FDA follows the product's six-month expedited review by FDA under its priority review program, which has been used to approve other breast cancer therapies such as trastuzumab, lapatinib and pertuzumab.
Kadcyla's approval marks only the fourth product approved to treat breast cancer targeting the HER2 protein, and the third in six years. A fifth treatment, Avastin (bevacizumab), was stripped of its breast cancer indication in 2011 after FDA officials said that it was unable to show that the product was safe or effective. Avastin had been approved for the condition based on surrogate endpoints in 2008.
Kadcyla, known as TDM1 during its clinical trials, was tested in a study of 991 patients, who benefited from an additional 5.8 months of overall survival and 3.2 months of progression-free survival (PFS) relative to a control group treated with lapatinib (Tykerb, GSK) plus capexitabine (Xeloda, Roche).
The drug is being approved with a Boxed Warning due to its potential to cause liver toxicity, heart toxicity, birth defects and death. More common side effects include nausea, fatigue, muscle or joint pain, low blood platelet levels, increased levels of liver enzymes, headache and constipation.
The drug is marketed by Roche subsidiary Genentech. The company highlighted the drug's six-month benefit to overall survival.
Genentech also said the drug would be available to consumers within two weeks, but the costs could be prohibitive to some. In a separate statement, Genentech said the drug would cost $9,800 per month of treatment, of $94,400 per year. The treatment is cheaper on a per-month basis than Tykerb and Xeloda taken together ($10,460 per month).
The company said its patient assistance program will pay 80% of a patient's out-of-pocket costs for the drug, "up to $9,000 or $24,000 per year, depending on the person's income."