ASCO: Cetuximab Plus Platinum Extends Head and Neck Cancer Survival

CHICAGO, June 2 -- Adding the monoclonal antibody cetuximab (Erbitux) to standard platinum-based chemotherapy for first-line treatment of head and neck cancers prolongs overall survival, researchers said here.

In a European trial, combination therapy improved survival by 2.7 months on average compared with chemotherapy alone (P=0.0362), found Jan B. Vermorken, M.D., Ph.D., of the University of Antwerp, Belgium, and colleagues.

The results, presented at the American Society of Clinical Oncology meeting, are among the longest survival benefit ever seen in such a trial, Dr. Vermorken said.

"This is the first systemic treatment in 25 years to show a survival benefit over platinum-based chemotherapy" for these patients, he said.

"We have now found for the first time--in a group of patients with a very poor outcome--a survival benefit that will change practice," he added.

Cetuximab is FDA approved for the treatment of locally or regionally advanced head and neck cancer in combination with radiation therapy or alone for patients with recurrent or metastatic disease. It is not yet approved for first-line treatment.

To see if it would be effective in first-line treatment, the researcher conducted the EXTREME trial (Erbitux in First-Line Treatment of Recurrent or Metastatic Head and Neck Cancer).

The multinational trial included 220 patients randomized to six cycles of 5-fluorouracil (Adrucil) plus either carboplatin (Paraplatin) or cisplatin (Platinol) every three weeks.

Another 222 patients were randomized to the same chemotherapy regimen with the addition of cetuximab at an initial dose of 400 mg/m² then 250 mg/m² weekly. Cetuximab was given until disease progression or unacceptable toxicity.

Participants had stage III or IV recurrent or metastatic squamous cell carcinoma of the head and neck that could not be treated with local therapy.

Dr. Vermorken described the study population-many of whom were heavy smokers and often alcohol users as well-as typical of patients with head and neck cancers.

The median age was 57. Most had cancer of the larynx or pharynx (25% and 47%, respectively). Nearly all patients were men (399).

Patients were not selected for epidermal growth factor receptor (EGFR) since nearly all squamous cell carcinomas of the head and neck express this marker, he said.

The researchers found that the mean survival was 10.1 months for the cetuximab combination treatment group and only 7.4 months for the chemotherapy alone group.

Dr. Vermorken said this difference was statistically and clinically significant (hazard ratio 0.797, 95% CI 0.644 to 0.986, P=0.0362).

Median survival for patients with recurrent or metastatic disease is typically around six to seven months, he noted.

The benefit did not appear to be at the expense of increased adverse events, Dr. Vermorken said.

"In the interim safety analysis, the addition of cetuximab did not modify the characteristic adverse event profile of platinum-based chemotherapy," he said.

The most common adverse events for both groups were anemia, neutropenia, thrombocytopenia, and dyspnea. The only notable difference was the higher incidence of an acne-like rash in the cetuximab combination group (less than 5% versus 0%), Dr. Vermorken said.