URB937 drug boosts natural painkiller level: Study

A new study has shown how a novel compound boosts levels of a natural painkiller at the site of an injury.

The ground-breaking study published today in Nature Neuroscience shows how the potential drug URB937 acts in peripheral tissue and may have the potential to relieve pain without the side effects associated with many current painkillers that act centrally on the nervous system.

The preclinical study by the Drug Discovery and Development (D3) unit of the Italian Institute of Technology and the University of California, Irvine, showed that URB937, a potent, second-generation inhibitor of the enzyme fatty acid amide hydrolase (FAAH), controlled pain and inflammation locally at site by boosting levels of anandamide in peripheral tissues, part of the analgesic and anti-inflammatory endocannabinoid system. The compound is the first FAAH inhibitor produced with restricted access to the central nervous system (CNS), whereas current FAAH inhibitors readily cross the blood-brain barrier.

Dr Daniele Piomelli, Scientific Director of D3, and lead investigator said: "These findings are significant because they show for the first time how FAAH inhibitors may enable the body to harness its own analgesic and anti-inflammatory powers right where the pain relief is needed and avoid side effects often seen in other painkillers. This has great potential to give patients more treatment options to relieve a wide spectrum of pain, such as rheumatoid arthritis and peripheral neuropathic pain."

By circumventing the CNS, the compound may have numerous therapeutic advantages over current pain treatments such as opiates and non-steroidal anti-inflammatory drugs (NSAIDs) that can cause unwanted side effects in some patients such as nausea, bowel irritation and dependency.

Andrew Rice, Professor of Pain Research at Imperial College London, said: "This paper represents an important advance in the development of clinically useful cannabinoids. The existing laboratory and clinical data unequivocally demonstrate that cannabinoids have pain relieving properties, but their therapeutic index needs to be improved. By using a strategy of inhibiting an enzyme which inactivates endogenous cannabinoid only outside the brain and showing that this approach is still sufficient to retain an analgesic effect, Professor Piomelli and his colleagues have made a significant advance."

D3 is continuing the development programme of URB937 and plans to begin clinical studies in 2012.

Investigators from other institutions were also involved in the study, including the universities of Urbino, Parma, Naples, and the Complutense University in Madrid.