September 11, 2015 — Tiny gas microbubbles can enhance the delivery and absorption of cancer drugs in patients with advanced pancreatic cancer, according to a new pilot study. The study was described at the International Contrast Ultrasound Society (ICUS) annual conference in Chicago.
One year after their last treatment cycle, two of 10 patients are still alive. 74 percent of pancreatic cancer patients die within the first year of diagnosis. The average life expectancy after diagnosis with metastic pancreatic cancer is just three to six months.
"Our early findings suggested that commercially-available ultrasound microbubbles, combined with a standard chemotherapy drug, might prolong survival in pancreatic cancer patients," according to Odd Helge Gilja, M.D., head of National Centre of Ultrasound in Gastroenterology at Haukeland University Hospital, in Bergen, Norway.
The pilot study included 10 patients with inoperable tumors, and preliminary results in 2014 showed that tumor size was reduced or growth was slowed in the patients, according to Gilja. "The patients treated with ultrasound sonoporation were able to undergo significantly more treatment cycles than those receiving standard chemotherapy. Additional studies are planned to confirm and potentially extend the results," he said.
"The findings are extremely exciting because this study appears to represent the first time ultrasound microbubbles have been used in patients for drug delivery," according to Steven Feinstein, M.D., co-president of ICUS and a professor of medicine at Rush University, Chicago. "If further studies confirm the Bergen findings, ultrasound microbubbles could prove to be an innovative platform option for delivery of drugs and genes to treat other cancers and a wide variety of medical abnormalities throughout the body," he said.
Gilja reported that all 10 patients who participated in the pilot Phase I study received an infusion of a standard chemotherapy drug, gemcitabine, followed by an infusion of a microbubble contrast agent. A customized commercial ultrasound scanner was then used to confirm the presence of the microbubbles in the vicinity of the tumor and to induce "sonoporation," a transient opening and resealing of cell membranes to allow for enhanced delivery and absorption of the cancer drug. Tumor sizes were confirmed by computed tomography (CT) imaging, according to Gilja.
Three ultrasound contrast agents — Definity (Lantheus Medical Imaging), Optison (GE Healthcare) and Lumason (Bracco Diagnostics) — are available in the United States but are approved by the U.S. Food and Drug Administration for cardiac imaging only.
For more information: www.icus-society.org