Two drugs already used to treat kidney cancer doubled survival in a rare form of pancreatic cancer known as neuroendocrine cancer or islet cell tumors, researchers reported Wednesday.
The tumors account for only about 1.4% of the 40,000 people who develop pancreatic cancer each year and are generally not as lethal as the adenocarcinomas that represent the bulk of pancreatic cancers. While patients with adenocarcinomas typically die within a year or two, those with neuroendocrine tumors can survive much longer.
Apple Chief Executive Steve Jobs was first diagnosed with the disease in 2003 and has subsequently taken three medical leaves from the company for treatment -- one to have a liver transplant necessitated by a tumor metastasis. The neuroendocrine tumors can frequently be treated by surgical removal, but when they do recur, there are few chemotherapeutic options. The two drugs, Pfizer's Sutent and Novartis's Afinitor, thus represent major new treatment options for patients with the disease. A third kidney cancer drug, Bayer's Nexavar, has also shown promise in treating the tumors.
The two reports in Thursday's New England Journal of Medicine described Phase 3 trials of the drugs, the last step before seeking Food and Drug Administration approval for marketing.
In the first study, Dr. Eric Raymond of the University of Paris and his colleagues originally planned to study 340 patients with advanced islet cell tumors, giving half Sutent -- known generically as sunitinib -- and half a placebo. But enrollment was halted after only 171 patients were collected because the results proved to be so promising. Patients taking the drug had no progression of their tumors for a median of 11.4 months, compared with a median of 5.5 months for those taking a placebo. The study was halted because it would have been unethical to continue giving placebo to patients, Pfizer said. When the study was halted, there had been nine deaths in the Sutent group (10%), compared with 21 in the placebo group (25%).
In the second study, Dr. James C. Yao of the University of Texas M.D. Anderson Cancer Center and his colleagues treated 410 patients with either Afinitor -- known generically as everolimus -- or placebo. They found that patients on Afinitor had no progression of their tumors for a median of 11 months, while the median was 4.6 months for those on placebo. They were not able to measure the effects on survival because patients on placebo were switched to the drug when their tumors began progressing.
"These studies provide optimism," write Dr. Robert T. Jenson and Dr. Gianfranco Delle Fave of the National Institute of Diabetes and Digestive and Kidney Diseases in an editorial in the same journal. "Both drugs are effective at improving disease-free survival, even in patients in whom other treatments have failed, and thus offer effective therapies where there were none before." Perhaps even better results could be obtained, they suggested, using the drugs in sequence or together.
But the drugs had several side effects, including canker sores, diarrhea, vomiting and infections. Those could present a problem, physicians said, because the drugs would, presumably, have to be taken for the rest of a patient's life.