By Cormac Sheridan
BioWorld International Correspondent
DUBLIN, Ireland - The National Institute of Drug Abuse (NIDA) agreed to fund the next stage in the development of NeuroSearch A/S's candidate treatment for cocaine addiction, NS2359.
Phase II clinical studies will begin in October, NeuroSearch President and CEO Jorgen Buus Lassen told BioWorld International, when enrollment of 24 cocaine users in the U.S. will commence.
"If we have good data out of the first study, we expect that NIDA will initiate a study next year with a higher number of cocaine addicts," Buus Lassen said.
Around the same time, the Ballerup, Denmark-based biopharmaceutical firm hopes to commence Phase I studies with the same compound in alcoholism. Wojciech Kostowski at the Institute of Psychiatry & Neurology in Warsaw, Poland, and other scientific collaborators in Europe and the U.S. are studying the compound in animal models of the disease, Buus Lassen said.
NS2359 is a dopamine reuptake inhibitor that NIDA selected for clinical trials because animal studies indicated that it prevented self-injection of cocaine, without altering behavior. Cocaine use leads to a large release of the neurotransmitter dopamine, which in turn stimulates a reward center in the brain and induces a feeling of euphoria. NS2359 is thought to offset a subsequent sharp reduction in the function of this brain region, an effect associated with cocaine withdrawal and subsequent craving. In animal studies, NS2359 had a weak but sustained effect that became apparent several hours after its administration.
The initial Phase I study, which was conducted in the UK, indicated the compound was well tolerated in healthy volunteers. The only difference compared to the placebo, said Buus Lassen, was a higher frequency of sleep disruption at very high dose levels, above the expected therapeutic dose.
The Phase II study will enable the company to examine how NS2359 interacts with cocaine, as some of the participants will take the latter drug in conjunction with the therapy. The preclinical studies in animals indicated that it offset the cardiovascular as well as the central nervous system effects of cocaine abuse.
NIDA has not taken any royalty position in the development program. NeuroSearch will, with its help, seek a partner for Phase III studies.
"NIDA will participate, but they will not fund it all," said Buus Lassen, adding he expects to partner with a small- or medium-sized pharmaceutical company. The revenue potential of the treatment is not sufficient to attract a major pharma company, he said, citing an NIDA estimate that it could yield annual sales of $200 million to $300 million. "I don't know how valid this estimation is," he said. "But 1 million to 2 million Americans are thought to be dependent on cocaine."
NeuroSearch's stock, which is quoted on the Copenhagen Stock Exchange, rose DKK 18, or 4.6 percent, on the news Monday to close at DKK 410.