(Adds background, researcher comment)
April 18 (Reuters) - U.S. regulators have expanded use of AstraZeneca's lung cancer drug Tagrisso to include initial treatment of patients with a specific genetic mutation, the company said on Wednesday.
The latest Food and Drug Administration approval includes patients with metastatic non-small cell lung cancer whose tumors have epidermal growth factor receptor (EGFR) mutations as detected by an FDA-approved test.
Tagrisso, also known as osimertinib, was already approved for use in patients whose lung cancer worsened after treatment with other EGFR therapies and who have developed a secondary mutation.
The first-line trial found that patients on Tagrisso went 18.9 months on average before their disease worsened, against 10.2 months for those given older medicines that act in a similar way.
"Osimertinib provides robust improvements in progression-free survival with no unexpected safety signals compared to the previous generation of EGFR inhibitors," Dr. Suresh Ramalingam, principal investigator of trial, from Winship Cancer Institute of Emory University, Atlanta, said in a statement.
Drugs like Tagrisso designed for patients with certain EGFR mutations can hold disease at bay in these patients, but cancer cells often adapt and develop new resistance mechanisms.
The pill is under regulatory review in the European Union and Japan for use in the first-line treatment setting, and regulatory decisions are expected in the second half of 2018, the company said.
AstraZeneca has predicted that Tagrisso will become a $4 billion-a-year seller. (Reporting by Mekhla Raina in Bengaluru and Deena Beasley in Los Angeles Editing by Sandra Maler and Cynthia Osterman)