April 6 (Bloomberg) -- Wyeth said U.S. regulators will take an additional three months to review its kidney cancer drug Torisel, the first of five new medicines the company hopes to introduce this year.

The Food and Drug Administration needs more time to review data on tumor growth in patients taking Torisel, the company said today in a statement. Torisel would join Pfizer Inc.'s Sutent and Bayer AG's Nexavar as the first drugs in two decades to effectively hold off incurable kidney cancer, doctors say.

``We are encouraged by the review process so far,'' said Robert Ruffolo, president of Wyeth Research, in the statement. ``With the submission of these analyses, we remain optimistic about the prospects for strengthening the product labeling for launch in the third quarter of 2007.''

Wyeth needs new drugs to replace Effexor, the world's top- selling antidepressant with $3.7 billion in sales in 2006, when that drug loses patent protection in three years. The Madison, New Jersey-based company says Torisel may one day generate $500 million in annual sales, while experimental drugs for menopause, contraception and schizophrenia might add about $5 billion a year once approved, the company said.

``In order for Wyeth's growth to remain solidly in the high single digits or low double digits, potential from the pipeline will have to be realized,'' said Mario Corso, an analyst with Summer Street Research Partners in Boston, in a note to clients.

Shares of Wyeth, based in Madison, New Jersey, rose 39 cents to $52.86 yesterday in New York Stock Exchange composite trading. Stock exchanges in the U.S. are closed today for Good Friday.

Survival Prolonged

The Wyeth drug prolonged survival by 50 percent in a study of the sickest type of kidney-cancer patients, while Sutent and Nexavar, both introduced last year, slowed tumor growth in tests. About 51,000 Americans will be diagnosed with kidney cancer this year.

The medicines block the growth of cancer cells, a different mechanism from chemotherapy, which kills tumors and can harm nearby tissues. Torisel will cost patients as much as $30,000 a year, Corso said.

Nexavar posted $165 million in revenue in its first year, and Sutent generated $104 million. Torisel would have annual revenue of $250 million if doctors reserve it for the sickest patients, and $1 billion if it is prescribed as a first choice for healthier patients, instead of Sutent, Corso said.

Torisel kept the sickest kidney-cancer patients alive an average of 10.9 months, compared with 7.3 months for an older remedy, interferon, according to studies Wyeth submitted to U.S. regulators. Torisel also postponed tumor growth for 5.5 months, 77 percent longer than interferon.

New Focus

Cancer is a new disease focus for Wyeth, said Deutsche Bank analyst Barbara Ryan, based in Greenwich, Connecticut.

``Wyeth has made a big commitment to oncology in their pipeline with Torisel and with the drugs that are further behind in testing,'' Ryan said in a telephone interview this week.

Wyeth may begin the final stages of testing for three experimental cancer drugs as early as this year, Ruffolo said. Within three years, Wyeth may be ready to seek U.S. regulatory approval for the new oncology products, he said.

One, called CMC-544, treats non-Hodgkin's lymphoma, a cancer that attacks the white blood cells responsible for immune response. Another, SKI-606, is for chronic myelogenous leukemia, a rare blood cancer. The third, HKI-272, is for breast cancer.

Other Drugs

By the end of this year, Wyeth might win FDA approval for Lybrel, the first contraceptive to completely eliminate monthly periods. The FDA is also poised to decide this year on two menopause drugs, Pristiq and Viviant. Bifeprunox, a schizophrenia remedy, also may be cleared in 2007.

All four drugs are manufactured at Wyeth's plant in Guayama, Puerto Rico, where the FDA recently finished a safety inspection for quality control failures, including the discovery of machine parts in drug packaging.

The FDA delayed approval for Pristiq in January, citing safety concerns at the plant. In June, regulators delayed clearance for Lybrel because of issues with manufacturing and side effects.

To contact the reporter on this story: Lisa Rapaport in New York at Lrapaport1@bloomberg.net

Last Updated: April 6, 2007 14:35 EDT