A drug designed to block a protein known to help cancer cells grow was shown in a mid-stage trial to lengthen survival in patients with advanced lung cancer that worsened after initial treatment, researchers said on Monday.
The results, presented at a meeting of the American Society of Clinical Oncology in Chicago, are the first time an agent in a class known as heat shock protein 90 inhibitors, HSP90 for short, has been shown to be safe and effective, they said.
Ganetespib, developed by Synta Pharmaceuticals, is designed to block HSP90, serving to knock out a pathway used by many different cancer-fueling proteins.
The Phase 2 trial, conducted by researchers from the Winship Cancer Institute of Emory University in Atlanta, involved 252 patients with late-stage lung adenocarcinoma, the most common type of lung cancer. It accounts for about 45 percent of the 170,000 non-small cell lung cancer cases diagnosed in the United States each year.
The study compared treatment with a combination of ganetespib and chemotherapy to chemotherapy alone. Patients on the drug lived for a median of 9.8 months, compared with 7.4 months for patients given just chemotherapy.
For patients whose cancer was diagnosed six months or more before the start of the study, overall survival improved to 10.7 months compared with 6.4 months - a gain of 67 percent.
That group of patients is being studied in a pivotal trial of ganetespib.
Side effects associated with the drug included low white blood cell levels, fatigue and diarrhea.
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