UPDATE 2-Pfizer liver cancer trial halted on safety concern

* Sutent trial stopped due to serious adverse events

* Still being tested against other cancers (Updates to simplify last paragraph)

NEW YORK, April 22 (Reuters) - Pfizer Inc PFE.N said on Thursday it has discontinued a late stage liver cancer study of its drug Sutent because of high incidence of serious adverse events suffered by patients taking the medicine.

Following a review by the independent Data Monitoring Committee the trial was halted over safety issues, Pfizer said.

Sutent is already approved to treat advanced kidney cancer and gastrointestinal stromal tumors following disease progression and had worldwide sales of $964 million in 2009.

Pfizer is testing Sutent against a wide range of cancers in hopes of significantly expanding sales of the drug.

The liver cancer failure represents the latest in a long list of clinical setbacks for the world’s largest drugmaker, including a Sutent failure in a late stage advanced breast cancer study announced last month.

The company has been widely criticized by analysts for its inability to deliver products based on its own research despite the industry’s largest research and development budget.

The company last year acquired Wyeth for $67 billion in large part to gain that company’s promising portfolio of drugs in development.

The halted open label trial tested Sutent against Nexavar, a liver cancer drug sold by Bayer AG BAYGn.DE and Onyx Pharmaceuticals Inc ONXX.O.

Safety monitors found higher incidence of serious side effects in patients taking Sutent, known chemically as sunitinib, compared with those who received Nexavar.

Sutent also failed to demonstrate that it was either superior or non-inferior to Nexavar in extending the survival of liver cancer patients, the company said.

“The disappointing outcome of this trial challenges all of us to work harder to understand the complex biology of this disease,” Mace Rothenberg, head of clinical development for Pfizer’s oncology unit, said in a statement.

Pfizer is still testing the drug against non-small cell lung cancer, prostate cancer and for kidney cancer following surgery. (Reporting by Bill Berkrot; editing by Carol Bishopric)