NEW YORK (AP) -- A potential Pfizer Inc. treatment for an advanced form of lung cancer missed its main goals in two late-stage studies, but the drugmaker said it is still waiting for results from a third study.

The New York company said Monday that dacomitinib failed to show a statistically significant improvement in progression-free survival in a study comparing it with the treatment erlotinib. It also missed its goal of prolonging overall survival when compared to a fake drug or a placebo in another study.

Both clinical trials involved patients with advanced non-small cell lung cancer who had tried other treatments. Progression-free survival measures the time from the start of treatment until a patient's cancer begins advancing again or the patient dies.

Dacomitinib also is being compared to another treatment, gefitinib, in a third, late-stage study involving patients who had no prior treatment. Results from that are expected next year.

Late-stage studies are typically the last and most expensive phase of clinical research before a drugmaker submits a treatment to regulators for approval.

Dacomitinib is an oral drug designed to be taken once a day. It has yet to receive regulatory approval in any country.

Pfizer shares edged up 2 cents to $30.11 in premarket trading Monday. Its shares are up more than 12 percent over the past year.