Iressa (gefitinib) by AstraZeneca Pharmaceuticals will soon be available as another first-line treatment option for patients with metastatic non-small cell lung cancer (NSCLC) whose tumors are composed of certain types of epidermal growth factor receptors (EGFR) mutations, as diagnosed by a test approved by the FDA. Iressa’s prior orphan product designation helped fast track it to approval.

Iressa, classified as a kinase inhibitor that works by blocking proteins responsible for driving cancer growth with certain EGFRs, is indicated for tumors that express the most common types of mutations in NSCLC. FDA-approved therascreen EGFR RGQ PCR Kit will serve as a complementary diagnostic test to screen which patients will respond best to treatment with the drug.

“Iressa offers another effective first-line therapy option for selected lung cancer patients. This approval provides further support for a highly targeted approach to treating cancer,” said Richard Pazdur, M.D., director of the Office of Hematology and Oncology Products in the FDA’s Center for Drug Evaluation and Research.

“The approval of the therascreen EGFR RGQ PCR Kit will allow physicians to identify non-small cell lung cancer patients who are candidates for receiving Iressa as first-line therapy,” said Alberto Gutierrez, Ph.D., director of the Office of In Vitro Diagnostics and Radiological Health in the FDA’s Center for Devices and Radiological Health. “Companion diagnostics provide information that is essential for the safe and effective use of important medications.”

The drug’s approval was largely based on the positive results of a multi-center, single-arm clinical study involving 106 patients with EGFR mutation-positive metastatic NSCLC, without history of prior treatment. Primary endpoint was assessed as the percentage of patients found to have either complete or partial disappearance of tumors. Participants were given a once-a-day 250mg dose of Iressa. Investigators found that half of the participants had a shrinkage in tumor size, an effect that lasted 6 months on average. Response to treatment was found to be comparable whether the tumors had EGFR exon 19 deletions or exon 21 L858R substitution mutations.

Some of Iressa’s rare adverse effects include interstitial lung disease, liver damage, gastrointestinal perforation, severe diarrhea and ocular disorders, with the more common, minor side effects including diarrhea and skin reactions (including rash, acne, dry skin and pruritus, or itching).

To learn more about Iressa (gefitinib), visit http://iressa.com.