ECC 2015: Lung and Gastrointestinal Neuroendocrine Tumors and Results From the RADIANT-4 Trial
An international team of researchers has shown that the use of the mTOR inhibitor everolimus can delay tumor growth among both gastrointestinal and lung neuroendocrine tumors. This is particularly important for patients with lung tumors, the researchers say, because there is currently no approved treatment for such cases.
James Yao, MD, Chair of the Department of Gastrointestinal Medical Oncology at The University of Texas MD Anderson Cancer Center, reported on the results of the RADIANT-4 trial, a placebo-controlled, double-blind, phase III study carried out in centers in 13 European countries, Korea, Japan, Canada, and the United States. He described the results on September 27 at the 2015 European Cancer Congress in Vienna, Austria (Abstract 5LBA).
The treatment had a significant effect in nonfunctional neuroendocrine tumors—those that either do not secrete a hormone, or secrete one that does not cause symptoms, and are therefore often diagnosed later, when the cancer has become advanced. “About 80% of all neuroendocrine tumors are thought to be nonfunctional, so, unfortunately, late diagnosis is common and poses a major problem for these patients,” said Dr. Yao.
Trial Details
The trial included 302 patients with a median age of 63. After randomization, 205 received everolimus, and 97 received a placebo. The most common tumor sites were lung (30%) and ileum (24%). In the everolimus group, 53% had had prior therapy with somatostatin analog (SSA), chemotherapy (26%), and/or radiotherapy (22%). SSAs are widely used in neuroendocrine tumors to reduce hormone secretion, thereby inhibiting tumor growth and reducing symptoms. Although they are effective in gastrointestinal tumors, there is as no evidence that they delay tumor growth in lung neuroendocrine tumors.
In the placebo group, 56% had had prior SSA treatment, 24% chemotherapy, and 20% radiotherapy.
When progression-free survival was assessed, the investigators found an important difference between the two groups. “We found a statistically significant 52% reduction in the risk of progression or death in favor of everolimus, and also a clinically meaningful 2.8-fold (7.1-month) improvement in median progression-free survival compared with those who had taken placebo. In addition, everolimus was well tolerated by the patients, and its safety profile was good. We also saw a trend toward an improved overall survival, but the overall survival analysis is an interim one, and it is too early to be able to be more definite about that at this time,” Dr. Yao said.
“Although we knew from previous studies that everolimus could delay the growth of pancreatic neuroendocrine tumors, this is the first time we have been able to conclusively show that it is effective in other neuroendocrine tumor sites. We hope that our results will provide a new treatment option for lung and gastrointestinal neuroendocrine tumors, and we look forward to reporting further results from the trial, including those on final overall survival and quality of life.”
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