TDM-1 and Metastatic Breast Cancer
The early reports on the new drug, TDM-1 (catchy name, no?), are exciting. Although still in clinical trials and not yet available for other purposes, TDM-1 is demonstrating real potential as a treatment for her2 positive metastatic breast cancers. The simple explanation is that this drug combines a chemotherapy agent with herceptin, and the drug is taken right into her2 positive breast cancer cells--and then kills them. I know several women who are receiving TDM-1 and it is helping all of them. The most impressive is a woman who has been living with metastatic breast cancer for 7 or 8 years; after two doses of TDM-1, all the palpable lymph nodes (of which she had many) vanished, and her most recent scans looked normal. Now, sadly, we all know that the cancer will come back again, but that may not happen for a long time. We hope.
A reminder about the normal sequence of drugs tested in clinical trials: They are almost always first used for people with advanced/metastatic cancer. If they show promise in that setting, they gradually move into a larger population and are usually eventually offered as part of adjuvant treatment for women with early breast cancer. If these good results continue, that will likely happen with TDM-1. Here is the beginning of comments from Breast Cancer.org and then a link:
T-DM1 Improves Survival in Women with HER2-Positive Metastatic Breast Cancer
New results from the EMILIA study show that women diagnosed with HER2-positive metastatic breast cancer that had stopped responding to a standard targeted therapy regimen lived longer with or without the cancer growing (overall survival) when they got the experimental medicine T-DM1 compared to women who got a different targeted therapy regimen.
The results were reported by Genentech, the company that makes T-DM1, and will be presented at an upcoming professional meeting.
T-DM1 is a combination of the targeted therapy medicine Herceptin (chemical name: trastuzumab) and the chemotherapy medicine emtansine. In T-DM1, the emtansine is attached to the Herceptin.
(In earlier studies on T-DM1, it was reported that the chemotherapy medicine maytansine was attached to Herceptin to form T-DM1. Emtansine is a derivative of maytansine.)
Herceptin is approved by the U.S. Food and Drug Administration (FDA) to treat advanced stage, HER2-positive breast cancers and to lower the risk of recurrence of early-stage, HER2-positive breast cancer with a high risk of recurrence. HER2-positive breast cancers make too much of the HER2 protein. The HER2 protein sits on the surface of cancer cells and receives signals that tell the cancer to grow and spread. About one out of every four breast cancers is HER2-positive. Herceptin works by attaching to the HER2 protein and blocking it from receiving growth signals.
Emtansine, like some other chemotherapy medicines, disrupts the way cells grow. Emtansine isn't a targeted medicine, which means it can affect healthy cells as well as cancer cells.
T-DM1 was designed to deliver emtansine to cancer cells in a targeted way by attaching emtansine to Herceptin. Herceptin then carries emtansine to the HER2-positive cancer cells.