Doctors have successfully countered breast cancer using a drug named T-DM1, which delivers a toxic load on tumour cells without affecting the healthy cells. This drug is considered as the first ‘smart bomb’ on breast cancer.
Tested on nearly 1,000 women with advanced disease, the drug could manage to control the disease from getting worse during the experimental treatment that was conducted for several months. Moreover, the drug has also proven to be effective in improving the survival of breast cancer patients. After two years of treatment with the drug T-DM1, 65% of women were alive in comparison to 47% of women who received two standard cancer drugs.
Considering the margin of difference in women alive using this drug and the standard cancer drugs, the researchers are declaring the new treatment to be a winner. They are expecting the benefits of the drug to become more lucid with time. Being true, the number of women alive due to the new treatment is so many that the researchers couldn’t determine the average survival for the group yet.
“The absolute difference is greater than one year in how long these people live,” said Dr. Kimberly Blackwell of Duke University, who led the study. “This is a major step forward.” It is to be noted that the drug is still experimental and is not available for sale. However, the supporters of the drug expect the drug to reach the market within a year.
The treatment develops Herceptin, which is the first gene-targeted therapy for breast cancer. About 20% patients whose tumours overproduce a certain protein used it. Herceptin is very toxic and can’t be given by itself. Therefore, the researchers combined Herceptin with chemotherapy along with a chemical that maintain link between the two until they reach a cancer cell to release the poison for killing the cell.
Although Herceptin is just a substance capable of fastening the cancer cells as it encounters them, this dual weapon drug called T-DM1 is considered as the ‘smart bomb’ by the researchers. Doctors tested T-DM1 on 991 women, which were suffering from severe breast cancer that was widely spread and was getting worse despite treatment with chemotherapy and ordinary Herceptin. The women were provided either T-DM1 infusions every three weeks or Xeloda plus infusions daily containing Tykerb pills, which is the only alternative treatment approved for such cases.
The cancer of the women treated with the T-DM1 got worse nearly after 10 months median time compared to merely over 6 months for the others. Blackwell said that the magnitude of benefit is same as is seen with Herceptin initially, which later proved to enhance overall survival of breast cancer patients.
In addition to this, the drug T-DM1 also causes fewer side effects compared to other drugs. Amongst the women on treatment with T-DM1, few were detected with signs of liver damage and low levels of factors responsible for helping blood clot. However, most of the women on T-DM1 were not facing usual problems of chemotherapy. “People don’t lose their hair, they don’t throw up. They don’t need nausea medicines, they don’t need transfusions,” said Blackwell.
Three years ago, a 51-year old woman, Denise Davis was diagnosed with widely spread breast cancer that reached her liver and even bones. Since February 2011, she has been making trip to Duke in Durham, N.C., every three weeks for receiving infusion of T-DM1. “I call it Herceptin-plus,” Davis said. Scans every six weeks show “everything is still shrinking or stable,” she added. “Right now, I’m feeling pretty good about it. The only way I’d feel a little better is if it took care of everything, but I’ll take what I can get.”
Subsidiary of the Swiss company Roche, Genentech is looking forward to seek approval to sell the drug in Europe and United States later this year. Genentech has not determined the price of the drug T-DM1 yet. Herceptin costs over $4,000 a month along with the additional charges that doctors ask for infusing it.
Another company named ImmunoGen Inc. has developed the technology in combination with the drugs.