Special Segment: New Breast Cancer Drug

October 6, 2011 8:30:38 PM PDT
When it became available more than a decade age, Herceptin marked the beginning of a new generation of targeted treatments. Now a souped-up, experimental version of the drug may not only help patients live longer but cause fewer side effects.

Stacey Peters is the picture of health. She does triathlons, half marathons and 40-mile bike rides. But that's not the whole story.

"I found a lump myself that I knew had not been there before," said Peters.

For the past 13 years, Peters has been living with advanced breast cancer. She has a particularly aggressive form of the disease.

Peters, like an estimated 20-25 percent of breast cancer patients, is Her2 positive. Her2 refers to a type of breast cancer that has been found positive to carry a protein that promotes the growth of cancer cells.

Years ago the prognosis was dismal. But Peters is proof we are living in a whole new era. What used to be considered a death sentence can many times now be treated as a chronic condition such as heart disease and diabetes.

"So when one treatment stops we move onto the next," said Peters.

The blockbuster drug Herceptin helped keep Peters healthy. It's a targeted treatment for breast cancer that's taken after initial treatment. But eventually resistance can develop.

Enter an experimental drug some are calling "super Herceptin". It works like the original drug by hunting down and interfering with the cancer cells. But this newer version, called TDM1, is Herceptin with a chemotherapy drug attached. The combination delivers a one-two punch, seeking out the cancer cells and not only stopping growth but delivering the chemo right to the cell.

"The tumor cell basically eats the TDM1 and then the TDM1 gets release and just destroys the tumor cell from the inside out," said Dr. Melody Cobleigh, breast oncologist and researcher, Rush University Medical Center.

Trials of the drug are under way at many centers, including University of Chicago and Rush University Medical Center.

Peters is now taking the experimental medication. Dr. Cobleigh is her doctor.

"She went into remission almost immediately and has been on the drug almost a year," said Dr. Cobleight.

"The hope now with this medication is to target that chemo to the cancer cells and lead to improved outcomes and also fewer side effects," said said Dr. Rita Nada, breast oncologist, University of Chicago Medical Center.

And that is what research seems to be showing TDM1 stops the cancer in its tracks and not only increases survival rates but has fewer side effects including no hair loss.

"If anything, it is potentially improving on Herceptin," said Dr. Nada.

It also offers the promise of improved cure rates for women with early stages of the disease.

"It's just a terrific advance," said Dr. Cobleigh.

So what I hope and everybody hopes is that this drug moves in the early treatment of breast cancer."

Peters is taking TDM1 as part of a research trial to not only help herself but pave the way for others.

"To be able to provide data for someone that could benefit years down the road is extremely important for me to be able to give back," said Peters.

Researchers say there are still questions about how this drug will do long-term. About a year ago the manufacturer Genentech asked for accelerated approval from the FDA to start selling TDM1. The FDA said no and asked for more data. Various trials are under way.

Rush University Medical Center
University of Chicago Medical Center


Genentech has a support line for people interested in more information about the clinical trials for TDM1. 888.662.6728

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