Federal health regulators say OSI Pharmaceutical's Tarceva slows the progression of lung cancer when given to patients who have received chemotherapy.

OSI wants the Food and Drug Administration to approve Tarceva as a maintenance therapy, or a drug designed to stop cancer from spreading in patients who respond to chemotherapy. It is currently approved as a secondary treatment for patients who have not responded to chemotherapy.

A company study showed Tarceva lengthened patients lives about three months when taken immediately following chemotherapy.

The FDA on Wednesday will ask a panel of outside experts to compare Tarceva's performance with a similar drug marketed by Sanofi Aventis.