CHICAGO Doctors have successfully dropped the first "smart bomb" on breast cancer, using a drug to deliver a toxic payload to tumor cells while leaving healthy ones alone. In a key test involving nearly 1,000 women with very advanced disease, the experimental treatment extended by several months the time women lived without their cancer getting worse, doctors planned to report Sunday at a cancer conference in Chicago. More importantly, the treatment seems likely to improve survival; it will take more time to know for sure. After two years, 65 percent of women who received it were still alive versus 47 percent of those in a comparison group given two standard cancer drugs. That margin fell just short of the very strict criteria researchers set for stopping the study and declaring the new treatment a winner, and they hope the benefit becomes more clear with time. In fact, so many women on the new treatment are still alive that researchers cannot yet determine average survival for the group. "The absolute difference is greater than one year in how long these people live," said the study's leader, Dr. Kimberly Blackwell of Duke University. "This is a major step forward." A warning to … Continue reading →

A DRUG that delivers a powerful poison to tumours without some of the side effects of traditional treatments can delay the worsening of breast cancer and also appears to prolong lives, according to a new study. Besides representing an advance in treating breast cancer, the success in the clinical trial validates an idea that is being pursued by pharmaceutical companies to treat various types of cancer in a way that delivers drugs to cancerous cells while sparing healthy ones. ''We've envisioned a world where cancer treatment would kill the cancer and not hurt the patient,'' said Kimberly Blackwell, professor of medicine at the Duke Cancer Institute and the lead investigator in the trial. ''And this drug does that.'' Advertisement: Story continues below The drug, known as T-DM1, was developed by Genentech. The company plans to file for approval later this year. That could mean the drug will reach the market next year. T-DM1 and similar drugs under development consist of powerful toxins linked to proteins called antibodies. The antibodies latch on to cancer cells and deliver the toxic payload directly into those cells. Since the toxin is not active until it reaches the tumour, side effects are reduced. Such treatments, … Continue reading →