The Power of Herceptin
Safety Assessment
Kristina York

The Power of Herceptin

There was a time, not too long ago, when cancer was more or less unspoken. You rarely heard about someone’s diagnosis. The mere mention of the word terrified people because the disease was considered a death sentence.

Today, it’s a different scene. We have treatments that one could only have imagined 20 years ago. We’ve moved from an age of toxic drugs with no real specific targets, to targeted approaches based on tumor types.

UCLA cancer biologist Dr. Dennis Slamon spent the majority of his career studying one such subtype: human epidermal growth factor receptor 2 (Her2). His research focused on developing a cancer agent that could specifically target cells that were over-expressing Her2. Tumors with this trait tend to be more aggressive, grow faster and spread at rates higher than other breast cancers. Her2 overexpression occurs in about 25% of breast cancers.

Dr. Slamon relentlessly sought out patients and researchers to join his cause. Luckily, they responded. Women suffering from such tumors, and with little hope of beating their cancer, signed up for clinical trials. Meanwhile, the biotech giant Genentech became involved with the discovery work and refinement of the process, and a recombinant monoclonal antibody known as trastuzumab was developed. Clinical trials began around the country.

Large-scale trials would eventually show that the immunotherapy, in combination with chemotherapy, reduced the risk of tumor recurrence by 52% and decreased the death rate by 33%. The targeted therapy also carried fewer side effects—such as nausea, hair loss or fatigue—normally associated with traditional chemotherapy.

But even before then, as results from clinical trials began trickling out, women all over the United States demanded access to a treatment that had not yet gained FDA-approval, and limited access was granted. The patient reaction was unprecedented in the field of cancer. The drug had become a lightning rod for thousands of desperate women hoping for a cure, and push for better treatments helped fuel a breast cancer activist movement that mirrored what was occurring among AIDS activists during the 1980s and 1990.

In 1998, Dr. Slamons’ agent was approved by the FDA for certain cases, and sold under the tradename Herceptin®.  In 2006, that very drug was approved for use in all HER2+ cancers and named the most promising treatment for women whose tumors produce excess growth factor. Today, it is also used in the treatment of certain kinds of gastric cancers.

You can learn more about the story of this breakthrough drug in “The Making of Herceptin® a Revolutionary Treatment for Breast Cancer”—by Robert Bazell.1 The published account reflects the triumphs of the new treatment and the stories of the many women who received the drug during the earliest trials. The story is one of bravery and determination, of trials and tribulations, and lessons learned.

The future of research and how companies are combating cancer was greatly influenced by the development of this monoclonal antibody. Since the approval of Herceptin®—at the time only the second monoclonal antibody to be licensed for the treatment of cancer—the FDA has approved about 10 more mAbs for certain cancers. Some are being used independently; others are being paired up with a chemotherapy drug, radioactive particle or a toxin.

Clinical data is mixed. Even, Herceptin®—one of the most widely used mAb for cancer—is associated with cardiac dysfunction in 2-7% of cases. Monoclonal antibodies are also expensive therapies—in part because of the work that has to be done to develop and test the possible health effects of each one.
Still, it is worthwhile reflecting on the many women who fought for the opportunity to receive Herceptin® before it was even approved, and how many lives they may have saved.

  1. R. Bazell. 1998. The Making of Herceptin, a Revolutionary Treatment for Breast Cancer.  Random House: New York.