Roche said that its experimental drug reduced progression of a certain type of breast cancer, in a press release on Sunday.

The drug, trastuzumab emtansine or T-DM1, is developed by Roche. It combines Herceptin and a chemotherapy agent.

"The encouraging efficacy, safety profile and quality of life results from the EMILIA study support our belief that trastuzumab emtansine may have an important role for patients with HER2-positive metastatic breast cancer. We are working with global regulatory authorities to submit these data as quickly as possible and hope that trastuzumab emtansine will soon be available to patients with this aggressive type of breast cancer," said Dr. Hal Barron, Chief Medical Officer and Head, Global Product Development.

The clinical trials involved 991 patients HER2-positive locally advanced or metastatic breast cancer. The patients' diseased had progressed after initial treatment for the cancer.

"What we saw was that close to 18 more out of 100 women were alive after two years because they got the new drug compared to older form of treatment," said Dr. Kimberly Blackwell, an oncologist at Duke University Medical Center and lead researcher in the present study, to ABC News.

The study found that patients on the experimental drug had better chances of living after two years (64 percent versus 47.5 percent).

Also, the cancer in people on TDM-1 worsened later than in people who were on a combination of other drugs.

"This is very unusual for cancer drug trials. In many drug trials with improved outcomes, we see worse effects, but in this trial, we use two drugs, see better outcomes and have better quality of life measures," said Blackwell.

"TDM-1 is really a magic bullet in that it is designed to use the power of Herceptin to seek out cancer cells and then liberates inside those cells a very powerful drug," said Dr. Louis Weiner, an oncologist and director of the Georgetown Lombardi Comprehensive Cancer Center, to Reuters. Dr Weiner was not part of the present study.