A multicenter phase III clinical trial has demonstrated that nab-paclitaxel (Abraxane) plus gemcitabine extends the survival of late-stage pancreatic cancer patients compared with standard treatment. The MPACT (Metastatic Pancreatic Adenocarcinoma Clinical Trial) found the combination was well tolerated and resulted in clinically meaningful outcomes compared with gemcitabine alone, which is the current standard of care.
The pancreas is a gland behind the stomach that secretes enzymes into the upper part of the small intestine to help digestion. It also produces hormones, including insulin, which helps regulate the metabolism of sugars. The incidence of pancreatic cancer is increasing worldwide with an estimated 279,000 cases per year, including nearly 44,000 in the United States in 2012, and resulting in more than 37,000 American deaths last year.
Nab-paclitaxel wraps traditional chemotherapy, paclitaxel, in near-nano-sized shells of albumin, a protein that the tumor sees as food. The tumor uses various mechanisms to preferentially attract the albumin, which then acts like a Trojan Horse to release its package of chemotherapy inside the tumor. It is approved in the United States for metastatic breast cancer and non-small cell lung cancer.
“We are ecstatic that this clinical trial of Abraxane plus gemcitabine improves survival for patients with advanced stage IV pancreatic cancer,” said Daniel Von Hoff, MD, of Scottsdale Healthcare and TGen, in Phoenix, Arizona, and international lead investigator for MPACT. “It once again demonstrates that laboratory science-based medicine can make a difference for patients.”
MPACT is the largest phase III clinical trial completed in advanced pancreatic cancer with more than 800 patients. Findings from the study showed a 59% increase in 1-year median survival rates from less than a quarter of the patients (22%) to more than a third (35%). The 2-year survival rate for this cancer is negligible, less than 4%, but that more than doubles (9%) with the nab-paclitaxel/gemcitabine combination. The data was presented January 25th at the American Society of Clinical Oncology (ASCO) 2013 Gastrointestinal Cancers annual meeting in San Francisco, California.
The study showed significant improvement among some of the sickest patients including those with increased metastases. In addition, there was no increase in life-threatening toxicity. Other drug combinations that have demonstrated benefit have been limited by increased toxicities.
“This is a major improvement in a cancer with the lowest survival rates among all cancer types,” said Dr. Ramesh Ramanathan, medical director of Virginia G. Piper Cancer Center Clinical Trials at Scottsdale Healthcare and principal investigator for the clinical trial in the United States. “Advanced pancreatic cancer is fourth most common cause of cancer death in the United States and throughout the world. It is difficult to diagnose with a majority of the cases diagnosed at a late stage after the disease has already advanced.”