Pfizer's

(PFE) - Get Report

investigational drug Sutent more than doubled survival and significantly reduced tumor growth and spread in a Phase III study in patients with Gleevec-resistant gastrointestinal stromal tumors, the company said.

The drugmaker said encouraging Phase II results also were observed in other tumor types, including metastatic renal cell carcinoma, metastatic breast cancer and neuroendocrine tumors, according to data presented at the annual meeting of the American Society of Clinical Oncology.

Sutent is designed to starve tumors of blood and nutrients needed for growth and simultaneously kill cancer cells that make up tumors.

The results from a Phase III study of more than 300 GIST patients resistant to or intolerant of the standard treatment Gleevec, showed Sutent prolonged the time to tumor progression (6.3 months on Sutent vs. 1.5 months for controls) and reduced the risk of death by about 50% compared with a placebo, Pfizer said in a press release.

In addition, long-term follow-up data from the Phase I/II GIST study demonstrated that Sutent extended overall survival to nearly 20 months in patients whose cancer had progressed despite treatment with other standard therapies. Also, the median time to tumor progression in this study was 7.8 months for all patients, with some patients benefiting even more.

Gleevec is made by

Novartis

(NVS) - Get Report

.

Separate data were released from two Phase II studies of patients with resistant renal cell, or kidney, tumors. In a 63-patient trial, 40% of patients responded to treatment with Sutent. Tumors didn't progress for more than three months in an additional 28% of patients, indicating that 68% of patients benefited from the treatment, Pfizer said. The average time to tumor progression for patients in this study was 8.7 months, and the median overall survival was 16.4 months.

A second Phase II study of 106 patients demonstrated an objective response rate of 39% in patients treated with Sutent, the company said. Among the patients, 23% saw tumor stabilization. Taken together, a total of 62% of patients benefited from treatment with Sutent, Pfizer said.

Elsewhere, trial findings from

Bayer

(BAY)

and

Onyx Pharmaceuticals

(ONXX)

for the experimental drug sorafenib confirmed interim Phase III results in progression-free survival of advanced renal cell carcinoma. For more on that story,

click here.