A One-Two Punch Knocks HER2 Out

HER2 tumors go into complete remission following combo therapy

(RxWiki News) Cancer researchers are doing more with existing drugs - looking for other applications of some and combining therapies. A combination cocktail seems to work well with HER2-positive breast cancer.

Instead of using single agents alone, medical scientists have found that two approved drugs work better in controlling early-stage HER2-positive breast cancer.

"Ask if a drug combination could better treat your condition."

José Baselga, M.D., Ph.D, chief of Oncology at Massachusetts General Hospital (MGH) Cancer Center, led the study, which looked at adding Tykerb (lapatinib) to Herceptin (trastuzumab) to wage war against aggressive HER2-tumors that are seen in 20-30 of breast cancers.

Dr. Baselga says this is the first study that has shown the two drugs are more effective than single therapies when used prior to surgery.

"It opens up the concept of dual HER2 blockade as a better approach for patients with early, non-metastatic, HER2 breast cancer," he said in a news release discussing this research.

The current study  involves 455 patients in 23 countries. Patients all had untreated early-stage, non-metastatic (hasn't spread) HER2-positive breast tumors.

Participants were randomly selected to receive either intravenous Herceptin, oral Tykerb or both for six weeks.

The patients continued the therapy another 12 weeks, along with a weekly dose of the chemotherapy agent Taxol. The patients' tumors were surgically removed within four weeks of the last dose of their therapy.

After surgery, the women were given more chemotherapy and continued the same regimen for a total of one year of anti-HER2 treatment.

Of those patients who received the combined drug therapy, more than half achieved what's called "a pathological complete response." This means there were no signs of cancer found in tissue samples, and is considered a complete remission. In comparison, less than a third of the patients receiving only one drug had this level of response.

It's no surprise that the authors concluded the combined approach is superior to standard Herceptin treatment in improving the rate of remissions.

Patients who received the dual therapy will be followed to see how long they live - something that will be reported in a future study.

Both of these drugs are approved by the U.S. Food & Drug Administration to treat HER2-positive breast cancer. Herceptin is approved for postoperative therapy. Tykerb is combined with chemotherapy and used after surgery with patients who don't respond to Herceptin.

This research appeared in the January 17, 2012 issue of The Lancet.

The study was supported by GlaxoSmithKline, the company that manufactures Tykerb.

Review Date: 
January 17, 2012