• 11/16/2005
  • Philadellphia, PA
  • staff
  • NewsWise (www.newswise.com)

During the past decade, several new drugs have been approved that target specific genes and molecules, increasing survival for many cancer patients. Not only are these drugs often more effective than the current standards of care, they also carry an added benefit of fewer side effects. Many believe that a new generation of targeted therapies will be the first choice for cancer care in the future, with the goal of tailoring treatment to individual tumors and patients.

Clinical studies with several molecularly targeted drugs are being featured at the Annual International Conference on Molecular Targets and Cancer Therapeutics coordinated by the American Association for Cancer Research (AACR), the National Cancer Institute (NCI) and the European Organisation for Research and Treatment of Cancer (EORTC).
These include:

1. A Phase III trial, which has found that cetuximab (Erbitux) and radiotherapy improves disease control and survival rates for a specific category of advanced head and neck cancers.

2. A Phase II study, offering encouraging results that temsirolimus, a derivative of the immunosuppressant drug rapamycin, may be effective against recurrent and metastatic endometrial cancer.

Cetuximab Improves Locoregional Control and Survival of Locoregionally Advanced Head and Neck Cancer: Independent Review of Mature Data with a Median Follow-up of 45 Months (Abstract 2628)

Head and neck cancers account for three percent of diagnosed cancers in the United States, and almost 13,000 people will die each year from the disease. A majority of these cancers begin in cells lining the head and neck. Treatment for these patients usually consists of radiation therapy, chemotherapy combined with radiation treatment, or surgery followed by radiation and/or chemotherapy plus radiation for patients whose tumors can be surgically removed.

However, researchers are now finding that many head and neck cancer cells overexpress a protein called the epidermal growth factor receptor (EGFR), which may help cancer cells to grow more aggressively, that should lead to more targeted therapies.

A research group led by investigators from the University of Alabama at Birmingham conducted a phase III trial and found that cetuximab (Erbitux) improves disease control and survival rates when used in conjunction with radiotherapy in locoregionally (restricted to the pharynx/larynx and lymph nodes in the neck) advanced squamous cell carcinoma of the head and neck (SCCHN). The benefits were achieved with minimal increases to the toxicity experienced with radiation.

Cetuximab is a monoclonal antibody that binds specifically to EGFR on both normal and tumor cells, and competitively inhibits the binding of epidermal growth factor and other ligands, such as transforming growth factor–alpha. It is currently approved for the treatment of EGFR-expressing, metastatic colorectal cancer in patients who are refractory to irinotecan-based chemotherapy.

In the current trial, median survival was 49 months with cetuximab plus radiation and 29 months with radiation alone, coupled with a 26 percent reduction in mortality risk. The three-year survival rates for cetuximab plus radiation were 56 percent compared to 45 percent for radiation alone.

Four hundred and twenty four patients with locoregionally advanced SCCHN were randomized to one of two groups – radiation treatment alone or radiation treatment plus weekly cetuximab at an initial dose of 400 mg/m2 followed by 250 mg/m2 for the duration of radiation treatment. The median age of the patients was 57, and 80 percent were male. Patients were stratified according to Karnofsky performance status (which classifies patients according to their functional impairment and can be used to compare effectiveness of different therapies and assess the prognosis in individual patients), tumor stage, nodal involvement, and radiotherapy treatment fractionation regimen.

“We believe the combination of cetuximab and radiotherapy represents a unique therapeutic option for treating patients with locoregional SCCHN,” said James Bonner, M.D., a professor at the University of Alabama, Birmingham and lead investigator of the study. “These results will provide a much needed platform for additional efforts aimed at further improvements in outcomes.”

Source:
American Association for Cancer Research (AACR)