New Genetic Test Predicts Response to Targeted Therapies

[Christine 0]

Genzyme’s laboratory test to help identify non-small-cell-lung cancer (NSCLC) patients who may not respond to targeted therapies is now commercially available. Genzyme says its KRAS Mutation Analysis will help identify NSCLC patients who test positive for specific KRAS mutations, which have been associated with resistance to certain drugs, including the tyrosine kinase inhibitors (TKIs) Tarceva® (erlotinib) and IRESSA® (gefitinib).

"Between 15 and 30 percent of tumors from NSCLC patients have mutations in the KRAS gene and clinical studies show that this information plays an important role in making treatment decisions," says Mara Aspinall, president of Genzyme Genetics. "We believe this test will provide physicians and their patients with critical information to help determine how best to move forward with their treatment."

Recent clinical studies have shown that mutations in the KRAS gene are found more frequently in patients who show limited clinical response or who have a shorter time-to-disease progression with TKI treatment. A retrospective study published in a 2005 Journal of Clinical Oncology demonstrated a decrease in time-to-disease progression and in overall survival in KRAS mutation-positive patients when treated with Tarceva plus chemotherapy, versus chemotherapy treatment alone. Conversely, with TKI treatment, NSCLC patients with mutations in the epidermal growth factor receptor (EGFR) gene have shown improved response rates, and longer time-to-disease progression