Targeting HER2 in Lung Cancer

Non small cell lung cancer responds to Herceptin and other HER2 targeted therapies

(RxWiki News) You may have heard of HER2-positive breast cancer. You may not know that this gene can also play a role in lung cancer. And anti-HER2 medications may be useful in treating the world’s most common cancer.

Patients with non-small cell lung cancer (NSCLC) who have HER2 mutations may benefit from taking anti-HER2 medicines, according to a new study.

Herceptin (trastuzumab) and other targeted therapies were shown to keep advanced NSCLC from getting worse for just over five months.  

"Ask an oncologist if genetic testing of your tumor is advised."

Tumor cells can make too much of human epidermal growth factor 2 (HER2). This is called overexpression. The HER2 protein can also be altered, and these mutations can stimulate tumor cells to grow.

Only about 1 to 2 percent of lung cancers have HER2 mutations.

Researchers, led by Julien Mazières, MD, PhD, professor of pulmonology at Larrey Hospital in Toulouse, France, wanted to see if anti-HER2 medications could have an impact on these tumors.

“Our study suggests that many patients with HER2 mutations may benefit from anti-HER2 drugs," Dr. Mazières said in a news release.

Previous research showed no benefit from treating lung cancer patients with high HER2 levels with anti-HER2 medicines. This is the first study to look at using these drugs to treat HER2 mutations in lung cancer.

The researchers found that 65 out of 3,800 non-small cell lung cancer patients had HER2 mutations. These patients were identified from people living with NSCLC diagnosed in France, Spain and Switzerland.

Most of the patients in the study were women, about half of them had never smoked and 50 percent had stage IV disease.

Along with trastuzumab, other anti-HER2 medicines used in the study included Perjeta (pertuzumab) and Tykerb (lapatinib), Kinaction (masitinib, which is not yet approved in the US) and afatinib (under review in Europe and the United States).

A total of 16 patients with stage IV cancer were given chemotherapy and one or more of the anti-HER2 drugs. Some of these patients also received Avastin (bevacizumab).

Here’s what the study found:

  • 9 of the 16 patients had some tumor shrinkage after one round with trastuzumab.
  • After the second round of treatment (one with trastuzumab and the other with afatinib), tumors in two other patients shrank.
  • Tumor growth was suspended in three patients.
  • In patients who responded to the HER2 therapies, the disease did not get worse (progression-free survival, or PFS) for just over five months, which is twice as long as seen in patients who have two or three rounds of chemotherapiy.
  • Patients who received lapatinib and masatinib did not have extended PFS.

“This study, the largest to date dedicated to HER2-mutated NSCLC, reinforces the importance of screening for HER2 mutations in lung adenocarcinomas and suggests the potential efficacy of HER2-targeted drugs in this population,” the authors concluded.

This therapy won’t be available for one or two years, Dr. Mazières estimates. The data need to be confirmed in larger studies.

This study was published April 22 in the in the Journal of Clinical Oncology. Several of the authors reported financial relationships with Amgen, Boerhinger Ingelheim (maker of afatinib), Eli Lilly, GlaxoSmithKline (maker of Tykerb), Pfizer or Roche (maker of Perjeta).

Review Date: 
April 22, 2013