Killing cancer cells is easy when they are bathed in chemotherapy drugs in a laboratory dish, breast cancer specialist Kimberly Blackwell, MD, tells her patients.
But it’s far more complicated to eliminate cancer cells lurking in human bodies.
The very properties in chemotherapy drugs that effectively attack cancer also, unfortunately, attack normal, healthy cells. This conundrum is at the heart of the biggest challenge faced by cancer researchers and clinicians—to find a way of delivering drugs to kill cancerous cells while not harming healthy cells and tissue.
That goal appears to have been achieved by a breast cancer drug Dr. Blackwell studied as the lead researcher in a multinational clinical trial that has generated great excitement among other cancer researchers and physicians. It was approved by the U.S. Food and Drug Administration for the treatment of HER2-positive breast cancer in 2013. HER-2 positive, which comprises up to 25 percent of breast cancer patients.
Commercially known as Kadcyla -- but known during clinical trials as Trastuzumab emtansine or T-DM1 -- takes a powerful antibody (Herceptin) that is highly effective in treating HER-2 positive breast cancer tumors, and combines it with a second powerful chemotherapy agent. This approach ensures that the second “punch” of chemotherapy is delivered specifically to the HER-2 cancer cells targeted by Herceptin, and not to surrounding healthy cells. Some have referred to this as a “smart bomb” approach to treatment because of its specificity in targeting treatment only to diseased cells.