MONDAY, June 3, 2013 (HealthDay News) -- For patients struggling with a common and deadly form of lung cancer, adding the drug ganetespib to a standard chemotherapy drug may boost survival, new research suggests.
The finding centers on a class of medications known as heat shock protein 90 (Hsp90) inhibitors, and it's the first time in more than 10 years that researchers have uncovered a better way to treat this group of patients.
The findings were slated for presentation Monday in Chicago at the annual meeting of the American Society of Clinical Oncology.
"This is the first randomized study to demonstrate therapeutic benefit with a heat shock protein inhibitor in patients with cancer," study lead author Dr. Suresh Ramalingam, a professor of medical oncology at the Winship Cancer Institute of Emory University, in Atlanta, said in an ASCO news release.
The study focused on patients with a form of non-small cell lung cancer known as lung adenocarcinoma.
"We hope that the ongoing study will confirm our findings, as patients with this common form and stage of lung cancer urgently need more effective treatments," Ramalingam said.
The researchers said adenocarcinoma is the most common form of lung cancer. In the United States, it accounts for roughly 45 percent of the 170,000 non-small cell lung cancers diagnosed annually.
Ganetespib works by halting the function of newly established proteins that are involved in promoting the lung tumor's growth.
The new study was funded by drug maker Synta Pharmaceuticals and involved more than 250 patients, all of whom had tried standard treatments to no avail.
Half the patients were treated with the standard chemotherapy drug docetaxel, while the other half were given ganetespib in tandem with docetaxel.
Patients in the ganetespib group had longer average survival rates relative to those in the docetaxel-only group -- 9.8 months versus 7.4 months, respectively. Patients with advanced cancer that had been diagnosed at least six months prior to treatment saw a 67 percent boost in survival compared to similar patients who didn't get the new drug.
The researchers noted that prior trials on Hsp90 inhibitor drugs haven't panned out because side effects for patients were so dire. They said this is the first trial in which the drug has proven both safe and potentially effective.
Experts who weren't involved in the research were encouraged by the results.
"Ganetespib, in combination with docetaxel, shows promising early results in lung adenocarcinoma," Dr. Marjorie Zauderer, an ASCO spokeswoman and lung cancer expert, said in the news release. "We're hopeful about the outcome of an ongoing study, which could help more patients with this form of advanced lung cancer access this promising drug."
Dr. Len Horovitz, a pulmonary specialist at Lenox Hill Hospital in New York City, agreed.
"Finally there is a drug that can be offered to patients with advanced lung cancer, along with another drug," Horovitz said. "Ganetespib appears to increase overall survival independent of genetic markers. Since so many lung cancers are diagnosed at a late stage, this may help many patients."
Findings presented at medical meetings typically are considered preliminary until published in a peer-reviewed journal.
For more on lung cancer, head to the U.S. National Cancer Institute.
SOURCES: June 3, 2013, news release, American Society of Clinical Oncology; Len Horovitz, M.D, pulmonary specialist, Lenox Hill Hospital, New York City
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