Nearly 51 percent of patients with advanced non-small cell lung cancer that progressed following standard therapy obtain tumor shrinkage or stable disease with sunitinib, according to a presentation at the annual meeting of the American Society of Clinical Oncology.

The analysis represents the initial report from an ongoing phase II study is being conducted at several American and European centers. A total of 63 patients with non-small cell lung cancer received the first cycle of 50 mg sunitinib daily for four weeks followed by two weeks off treatment. Patients continue on treatment until disease progresses. Eligibility criteria included no recent gross hemoptysis, no brain metastases, and no response to one to two cycles of standard chemotherapy.

Six patients (9.5 percent) experienced partial tumor shrinkage and stable disease was achieved in another 26 patients (41 percent). Researchers continue to follow patients.

Sunitinib was generally well tolerated by the majority of patients. Most side effects were mild to moderate, such as fatigue, nausea, shortness of breath, vomiting, anorexia, and diarrhea. Serious side effects were less common and included severe fatigue (19 percent), shortness of breath (13 percent), asthenia (lack of energy; 9.5 percent), and nausea/vomiting (7 percent). Two patients died from pulmonary hemorrhage, and one died from bleeding in the brain.

The trial is being extended to explore a continuous dosing strategy of sunitinib 37.5 mg daily in addition to the original strategy of 50 mg daily for four weeks followed by two weeks off treatment.

“This is the first clinical trial to evaluate sunitinib alone in advanced lung cancer patients for whom prior therapy has failed,” said lead author Mark A. Socinski, MD, Associate Professor of Medicine at the University of North Carolina. “Our findings suggest that sunitinib may have a place in the treatment of lung cancer, alone or in combination with other agents.”

Sunitinib, which is taken orally once a day, inhibits several kinase enzymes in cancer cells, including vascular endothelial growth factor receptor (VEGFR). Sunitinib is already approved in the US for treatment of advanced kidney cancer and gastrointestinal stromal tumor. Other ongoing studies are evaluating the effectiveness of sunitinib in combination with therapies that target lung cancer in other ways, such as erlotinib.