BioWorld International Correspondent

LONDON - GW Pharmaceuticals plc has found a route to expand its portfolio beyond using cannabis extracts in the treatment of pain, signing a research and development agreement with Otsuka Pharmaceutical Co. Ltd., to develop cannabinoids in a range of central nervous system and oncology indications.

The research collaboration runs for three years, during which Otsuka will provide $9 million to fund basic research by GW Pharmaceuticals and its academic collaborators at the Aberdeen University. Compounds selected for formal development then will be outlicensed by GW to Otsuka, with the Japanese company funding global development and commercialization, while GW will supply the product and receive license fees, milestone payments and royalties.

"This is a fantastic arrangement, which provides GW with the ability to develop its portfolio without committing any of its own money," Justin Gover, managing director, told BioWorld International.

Otsuka specializes in central nervous system disorders, and the collaboration will focus initially on schizophrenia (where Otsuka has a marketed product), and bipolar and other mood disorders.

The compounds to be tested include a range of cannabinoids that GW has derived from its cannabis breeding program, which is carried out under a special license. "We have been breeding unique varieties, each one targeting a certain molecule," Gover said.

Increasing the content of particular molecules has made it viable to carry out research and to consider products that initially will be based on plant extracts. "We will also be looking at synthetic and semi-synthetic versions within the scope of the collaboration," he noted.

GW's other attraction for Otsuka is its relationship with Roger Pertwee, one of the pioneers in elucidating the cannabinoid receptor system. In research going back to 1968, Pertwee has shown that humans produce cannabinoids endogenously and that there are cannabinoid receptors in many different parts of the body, not just in the brain, as previously thought. In doing so, he has expanded the range of possible indications for cannabinoids.

Pertwee is professor of neuropharmacology at Aberdeen University and also director of pharmacology at GW, heading the company's Institute of Cannabinoid Research, which is based at the university.

Gover said he expects to see some compounds in the collaboration to progress to clinical trials quickly, since the Salisbury, UK-based company already has a thick safety file based on Sativex, its cannabis extract for treating symptoms of multiple sclerosis and pain. "The first product should be in trials in the course of the next year, and I would expect Otsuka to take out licenses within the three years of this agreement."

The two companies first linked up in February when they signed an agreement for Otsuka to develop Sativex in the U.S. In 2006 the FDA gave permission for the drug to go straight to Phase III in the treatment of cancer pain. Gover said a 336 patient trial will start in late 2007. A least one more trial will be required before the product can be filed for FDA approval.