The following is a guest post from Harold DeMonaco, MS, one of our expert editors on HealthNewsReview.org – and the one who, besides me, has analyzed more news stories in the past 6 years than anyone else on this project.
Journalists’ reporting on the information presented at the annual meeting of the American Society for Clinical Oncology (ASCO) is always interesting and this year is no exception. Cancer, after all, is a disease that can strike fear in the heart of just about everyone. So, it is understandable that many with the disease along with their friends and family members will be interested in realistic stories about new and promising treatments. But realism is not always present in the stories written about the ASCO meeting. Phrases that should never be used in a news report (breakthrough, miracle, stunning etc) seem to appear with some frequency. This year, stories about the results of a phase 3 trial of the experimental drug T-DM1 unfortunately follow the troubling trend of hyperbole and incomplete reporting.
This year’s media star of the ASCO meeting is a drug-antibody combination known as T-DM1 or trastuzumab emtansine. The phrase “smart bomb” appears in many of the stories we have seen, as does “magic bullet.” The phrase “magic bullet” was made popular in the 1940’s biopic film on the life of Dr. Paul Ehrlich and his development of a drug treatment for syphilis. Ehrlich envisioned his drug, salvarsan would selectively target the bacteria that caused syphilis and not produce any side effects. Although effective, salvarsan proved to be far less magical than it originally appeared, producing significant side effects. It was replaced with the discovery of penicillin, a far less toxic and more effective treatment.
T-DM1 is an antibody-drug conjugate and is designed to bind specifically to HER-2 receptors in breast cancer cells. Once bound to the HER-2 receptor, the toxic component (DM1) is released into the cancer cell. In theory the drug-antibody combination would only strike at HER-2 receptor positive cells while leaving normal cells unscathed. The results of the Phase 3 EMILIA study of T-DM1 in patents with advanced HER-2 receptor positive beast cancer were presented yesterday. And once again, many in the media appear to have only half read the report.
Here are a few of the story headlines I found online:
The Phase 3 EMILIA study compared T-DM1 with a standard regimen for HER-2 positive patients who have failed previous treatment with Herceptin and a taxane chemotherapy drug. About 500 patients were treated in each arm. Here are the interim results from the company’s press release:
As for toxicity, T-DM1 patients had fewer grade 3 or higher side effects (40.8%) compared to those who received standard treatment (57%). It is important to remember that these results are interim and the final story won’t be known 2014.
Here are a few of the snippets from the media’s reporting:
“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.” Balderdash. T-DM1 is clearly not without side effects and does not leave healthy cells alone.
“An experimental breast cancer drug from Roche Holding AG (ROG) that carries chemotherapy directly into malignant cells while bypassing healthy ones delayed tumors longer and with fewer side effects than an established therapy.” True, but let’s put the results into perspective. The drug does not bypass healthy cells and 40% of patients had severe side effects from T-DM1.
“An experimental drug has shown stunning results in delaying the progression of a specific type of breast cancer and prolonging the lives of patients.” Stunning? How stunning is a 3 month difference in disease progression and an absolute difference of 6.3% in one year survival?
“For patients facing metastatic breast cancer, this is a breakthrough.” Promising, yes. But it is not a breakthrough. At least not based on the interim report.
The ability to specifically target cancer cells is certainly a worthy goal and the development of T-DM1 is a clear step in the right direction. The drug worked in less than half the patients treated in prolonging the disease-free interval and was not without significant side effects. That’s better than anything available at the moment. But it is remains to be seen if it is a “magic bullet, smart bomb or miracle drug.”