ATLANTA (CNNMoney.com) - Sutent, an anti-cancer drug from Pfizer that's been on the market just a few months, shrank tumors and stopped them from spreading in the lungs and kidneys of patients, according to studies unveiled this weekend.

Sutent, a pill that is also called sunitinib, shrank or stabilized kidney tumors in 31 percent of patients who participated in a late-stage clinical trial that was funded by Pfizer, compared to 6 percent of patients who took the more standard intravenous cytokine drugs like Interferon.

These patients had not been previously treated for cancer.

This study could result in expanded use of Sutent, and more sales for Pfizer, the biggest drug maker in the world.

Also in the kidney cancer study, patients who took Sutent survived an average of 46 weeks without cancer spreading, while cytokine patients went 22 weeks without the cancer progressing.

In a separate study, Sutent shrank tumors in 51 percent of patients in the advanced stages of lung cancer, for whom other forms of treatment did not work. This lung cancer study was "phase 2," meaning that it was not as advanced as the "phase 3" kidney cancer study. Phase 3 is generally the most advanced stage of study before submitting a drug to the Food and Drug Administration for approval.

Dr. Mark Socinski, the lead researcher in the lung cancer study who is an associate professor at the University of North Carolina's oncology program, acknowledged that the study was still in the early stages, but said that Sutent "could have a place in the treatment of lung cancer, either alone or in combination with other agents."

In January 2006, Sutent was approved as a treatment for cancerous tumors in the gastrointestinal system, and for advanced kidney cancer patients who had failed treatment with Interferon. These two types of cancer are very different. "Even in early stages of development, we saw responses in different tumor types and we knew the drug could be active broadly," said Charles Baum, the leader of Pfizer's oncology drug development team.

These study results were announced at the annual conference of the American Society of Clinical Oncology. Pfizer, based in New York City, totaled $51.3 billion in 2005 sales. The company's top-selling drug is the cholesterol-cutting Lipitor, which totaled $12.2 billion in sales last year.

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From the annual conference of the American Society of Clinical Oncology:

• Favorable results for Glaxo breast-cancer drug
• Novartis improves on blood cancer treatment
• Sanofi blockbuster shown effective for head and neck cancer