NEW YORK - Pfizer Inc. may be the world's biggest drugmaker, but new chief executive officer Ian Read is taking charge at a trying time for the company, and he will have to deal with a declining share price, repeated failures of potential new products, and expirations of patents on key drugs.

Pfizer said Sunday that Read was replacing Jeffrey Kindler, who was Pfizer's CEO for 41/2 years. Read, 57, has worked at Pfizer for more than 30 years in a variety of positions and countries, making him a potential contrast to Kindler, who was an executive for McDonald's Corp. and a director of the New York branch of the Federal Reserve before he joined Pfizer.

New York-based Pfizer has large operations in the Philadelphia area due to its $68 billion purchase last year of rival Wyeth.

While Kindler's exit came as a surprise, analysts said the choice of Read indicates big changes are not immediately in store for the company.

Still, control of Pfizer could be shifting. Read is likely to have less say in Pfizer's direction than Kindler did because, unlike Kindler, he won't be the chairman of Pfizer's board. However, Read is getting the newly created role of company president.

Pfizer shares gained 9 cents to close at $16.81. The stock is down 9.6 percent over the last year.

Jefferies & Co. analyst Jeffrey Holford said Read was "a safe pair of hands," who is familiar with Pfizer.

But are larger changes needed? In late 2011, the patent on Pfizer's best-selling drug, the cholesterol medication Lipitor, will expire. This year the patents on Pfizer's antidepressant Effexor XR and Alzheimer's drug Aricept expired. More will follow, including billion-dollar sellers impotence drug Viagra, in 2012, and pain reliever Celebrex, in 2014.

The company has seen at least half a dozen drugs fail in the last stage of clinical testing in the last year and a half, including its Alzheimer's disease treatment Dimebon, osteoarthritis treatment tanezumab, and cancer drug figitumumab. Multiple trials that were designed to expand the marketing approval of its cancer drug Sutent also failed.

The company's pipeline difficulties continued Monday when it said its drug candidate bosutinib was not significantly better than another cancer drug at treating chronic myeloid leukemia. It said bosutinib did not outperform Novartis AG's drug Gleevec in a late-stage trial.

The company reported successes with studies of its lung cancer drug crizotinib and heart drug Inspra, and some studies of its blood thinner apixaban have been successful. But last month Pfizer stopped a trial because that drug was linked to an increased risk of bleeding.

Kindler sought to offset the pipeline expirations in part by wheeling and dealing, especially with the purchase of Wyeth. But analyst Les Funtledeyer of Miller Tabak & Co. said the Wyeth deal has not lived up to its billing so far - in contrast with Merck & Co. Inc.'s $46 billion purchase of Schering-Plough at about the same time. Last week, Merck named philadelphia native Kenneth C. Frazier as its new CEO.