(RxWiki News) A medication that’s used to treat a number of cancers in Japan could help people with pancreatic cancer live longer. The medication has been found to be most beneficial for Asian patients.
A phase III trial has shown that the chemotherapy agent S-1 helped Asian pancreatic cancer patients who have undergone surgery live longer than those treated with the standard therapy – Gemzar (gemcitabine).
S-1, which is already in use in Europe and Asian countries, is not yet available in the US. However, the therapy is currently being studied in a clinical trial here for its effectiveness in stomach cancer.
Results from this study may help speed its path to US Food and Drug Administration approval.
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Katsuhiko Uesaka, MD, PhD, medical deputy director at Shizuoka Cancer Center Hospital, led the study and presented findings at the American Society of Clinical Oncology (ASCO) 2013 Gastrointestinal Cancers Symposium.
Pancreatic cancer is highly lethal, with only about 6 percent of patients living past five years after diagnosis. The disease is usually detected late, when it may have already begun to spread (metastasize). Cancers that have started to spread aren’t good candidates for surgery.
For those who do have surgery to remove a pancreatic tumor, the standard post-operative (adjuvant) therapy that’s prescribed is Gemzar (gemcitabine). This medication, which extends life by several months, is used in this country to treat other cancers as well, including lung, bladder, ovarian and breast cancers.
This study looked at the difference in overall survival among 385 Japanese pancreatic cancer patients who were randomly assigned to receive either S-1 or gemcitabine after having surgery.
A total of 70 percent of patients receiving S-1 were alive after two years, compared to 53 percent of those taking gemcitabine. During that time, nearly half of the S-1 patients had not had a disease relapse, while 29 percent of the people in the gemcitabine group were free from relapse.
The researchers found that people taking S-1 had a 44 percent lower risk of death than those who took gemcitabine.
“Our survival data were much stronger than expected. Based on these results, we hope that guidelines for standard postoperative therapy for pancreatic cancer in Japan will be changed to replace gemcitabine with S-1 as single agent therapy,” Dr. Uesaka said in a statement.
These findings are not immediately applicable to Caucasian patients because of metabolic differences that cause more serious side effects - particularly diarrhea. As a result, lower doses are needed. Dr. Uesaka plans larger studies in Caucasians to be conducted in Europe and the US.
ASCO member and clinical oncologist, Neal J. Meropol, MD, who moderated a press briefing on studies being presented at the GI Symposium, said, “About a third of patients who present with pancreas cancer can undergo surgery with potentially curative intent. For the first time, we now have a another option that appears superior to gemcitabine in this setting – improving the cure rate in pancreatic cancer that is resectable [operable],” said Dr. Meropol, who is professor of Cancer Research and Therapeutics, and Chief of the Division of Hematology and Oncology at University Hospitals Case Medical Center and Case Western Reserve University.
S-1 was approved in 1999 in Japan to treat stomach cancer. It has since been approved for use in treating colorectal, head and neck, non-small cell lung, inoperable or recurrent breast, pancreatic and biliary tract cancers
Several of the study authors disclosed financial relationships with Taiho Pharmaceutical, the manufacturer of S-1 and Lilly Pharmaceutical. The research was funded by Taiho.
All research is considered preliminary before it is published in a peer-reviewed journal.