Roche aims for Kadcyla expansion with new early breast cancer data

Roche presented new data on Kadcyla at the San Antonio Breast Cancer Symposium on Wednesday. (Roche)

Roche is hoping to grow sales for new drugs as biosim competition begins to erode its top blockbusters, and now the drugmaker has unveiled new data that just might give its breast cancer drug Kadcyla a boost.

At the San Antonio Breast Cancer Symposium on Wednesday, Roche presented data showing post-surgery Kadcyla significantly beat Herceptin at improving invasive disease-free survival (iDFS) in HER2-positive, early breast cancer patients who didn't fully respond to drug therapy before surgery.

In its phase 3 Katherine study, which tested Kadcyla head to head against Herceptin in 1,500 patients, the newer drug improved patients' iDFS rate by more than 11% at three years, Roche said.

The data show Kadycla “represents a new treatment option for these patients who have a worse clinical outcome in that potentially curable setting," Roche's global head of breast and gynecologic cancer development, Jakob Dupont, told FiercePharma.

Many experts consider a 2.5% to 3% improvement in iDFS clinically worthwhile, Dupont said. He described the 11.3% result seen in the Katherine study as “remarkable.” 

“[W]ith our treatments that include Herceptin, Perjeta and Kadcyla that all target [HER2-positive breast cancer], we think that Katherine is the next step in our evolution to provide the best possible treatments,” he said.

Approved in 2013, Kadcyla contains Herceptin plus a chemotherapy called DM1. The so-called "armed antibody" initially carried sales expectations of up to $5 billion—and Roche had high hopes it would take the sting out of Herceptin copycats—but last year's sales rang in at just $925 million.

Obviously, a new market would be helpful, and Roche is discussing the new data with U.S. and European regulators, hoping to bring the drug to the patient group “as soon as possible," Dupont said.

The results come as Roche faces a growing biosimilar threat to its top cancer drugs, including Herceptin. Just last week, Celltrion and Teva won FDA approval for their biosimilar to Rituxan, a top performer for Roche. The biosim makers didn’t disclose their launch timing, but Roche has said it's expecting biosims to appear in the first half of next year. 

Meanwhile, Roche's Herceptin inches toward biosim competition under a deal the drugmaker made with Mylan and Biocon. Already armed with FDA approval for their biosimilar, the partners agreed to a mid-2019 launch date. Together, Herceptin and Rituxan pulled in nearly $7 billion in the U.S. last year.