FDA Highlights: Rapamycin shows pre-clinical potential in pancreatic cancer

by Bruce Sylvester: Rapamycin appears to shrink one type of pancreatic cancer tumor and prevents it from spreading, researchers reported on August 3, 2014 in the journal Gut.

“It’s a crucial step forward in developing new treatments for this devastating disease.” Said lead author Dr. Jennifer Morton of Cancer UK Beatson Institute at the University of Glasgow (Uk)

In previous clinical trials of rapamycin for pancreatic cancer, the drug was given to patients with all forms of the disease, and it did not show a general efficacy.

However, in this study, the investigators treated mice with pancreatic cancers caused by specific genetic faults. They found that a specific type of pancreatic tumor, caused by a fault in the gene PTEN, a gene involved in cell growth, appeared to respond to rapamycin.

In mice with faulty PTEN pancreatic tumors, rapamycin halted the spread of cancer cells. In some animals, the tumor shrank.

As background, the authors noted that rapamycin blocks a protein called ‘mammalian target of rapamycin’ (mTOR).This protein controls cell growth.

Prior research suggests that tumors caused by the faulty PTEN gene could depend on the mTOR protein for their growth.

Analyzing data on human pancreatic tumours, the Glasgow team found that about one-fifth of pancreatic cancer patients carried a faulty PTEN gene, suggesting potential benefit from treatment with rapamycin.

Dr. Morton said, “This is incredibly important research showing for the first time that there’s potential to tailor treatment to pancreatic cancer patients based on differences in their tumour’s genetic fingerprint. Although it’s at a very early stage, it’s the first time we’ve been able to pinpoint a genetic fault in pancreatic cancers and match it up with a specific drug.”

She added, “While more research is needed to see if this approach could benefit patients, it’s a crucial step forward in developing new treatments for this devastating disease which has seen no survival improvements since the 70s.”

Dr. Kat Arney, science communications manager at Cancer Research UK, said: “Over the next few years we plan to more than double the amount we spend on pancreatic cancer research to accelerate research into understanding the biology of this  disease and change the odds for patients.”