FDA OKs AstraZeneca’s Iressa for First-Line Treatment of Metastatic Lung Cancer

AstraZeneca’s kinase inhibitor Iressa received FDA approval last week as the first and only first-line treatment for patients with metastatic non-small cell lung cancer whose tumors have certain types of gene mutations, along with a companion diagnostic.

The drug has orphan product designation, giving it six years of marketing exclusivity.

Iressa (gefitinib), which blocks proteins that promote development of cancerous cells with epidermal growth factor receptor mutations, is intended for the most common of these mutations in NSCLC — exon 19 deletions and exon 21 L858R substitutions.

The FDA based its approval on a clinical trial of 106 patients with previously untreated EGFR mutation-positive metastatic NSCLC. Roughly 50 percent of patients saw their tumors shrink after taking a daily 250 mg dose, and the effect lasted an average of six months, the agency says. The response was similar regardless of the mutation.

In addition, the FDA approved Qiagen Manchester’s companion diagnostic, the therascreen EGFR RGQ PCR Kit, to determine patients appropriate for treatment with Iressa.

While Iressa is the first drug approved to treat these two mutations, there are over 40 other drugs indicated to treat NSCLC and other mutations, according to the National Cancer Institute. They include Novartis’ Zykadia (ceritinib), which was approved by the FDA in April 2014 to treat metastatic anaplastic lymphoma kinase-positive NSCLC, and Eli Lilly’s Cyramza (ramucirumab).

Iressa originally received accelerated approval from the FDA in 2003 for the treatment of patients with advanced NSCLC whose disease progressed on platinum doublet chemotherapy and docetaxel. A subsequent Phase 3 study failed to show the drug significantly prolonged survival and it was pulled from the market in June 2005. Last week’s approval is for a different patient population. — Kellen Owings