By Ransdell Pierson
(Reuters) - U.S. regulators have granted a "breakthrough therapy" designation to an experimental Pfizer Inc treatment for breast cancer, lifting the company's shares and putting a spotlight on its growing cancer-drug portfolio.
Analysts from JPMorgan and Leerink Swann forecast the oral medicine, called palbociclib, could generate annual sales of $5 billion or more if it is approved for use against breast cancer as well as other types of cancer.
Pfizer, whose stock rose 2.6 percent, said the U.S. Food and Drug Administration conferred the special status on palbociclib based on impressive results seen in mid-stage trials. The drug is now being tested in a larger Phase III study.
The FDA created the "breakthrough therapy" designation earlier this year for medicines deemed likely to demonstrate "substantial improvement" over existing drugs. It is intended to speed development and regulatory review of such medicines.
Leerink Swann analyst Seamus Fernandez said palbociclib could generate annual sales of $2.4 billion by 2020 if it is approved for breast cancer. He predicted the current study would show palbociclib slows tumor growth and prolongs life.
JPMorgan analyst Chris Schott called the FDA decision a "clear positive for Pfizer shares" and predicted palbociclib will be approved by 2016 or sooner thanks to acceleration under the "breakthrough" designation.
Palbociclib is being tested in combination with a standard drug, letrozole, in a Phase III trial of patients undergoing initial treatment for locally advanced or metastatic breast cancer.
Pfizer said interim data from the earlier mid-stage trials showed patients on the combined therapy went an average 26.1 months without a worsening of symptoms, compared with 7.5 months for patients taking only letrozole.
Palbociclib works by blocking two enzymes: cyclin dependent kinases (CDK) 4 and 6.
Pfizer, which has struggled in the past decade to come up with important new medicines, has won respect with recent approvals of three cancer drugs: Xalkori for lung cancer, Inlyta for kidney cancer and Bosulif for leukemia.
Pfizer shares were up 77 cents to $29.88 in early-afternoon trade, outpacing a 1.2 percent rise for the ARCA Pharmaceutical Index of large U.S. and European drugmakers.
(Reporting by Ransdell Pierson; editing by John Wallace)