DrugAbuse Sciences Inc. released data from a Phase III trial of Naltrexone Depot in patients being treated for alcohol dependence, getting low "p" values and showing benefit in those trying to kick the bottle.
Elizabeth Greetham, the company's CEO and chairman, said the company is holding back primary data pending release in a scientific forum, but said the 315-patient trial conducted at 29 sites in the U.S. is the first step toward a full package for the FDA.
Patients were given five sessions of motivational enhancement therapy - basically a "low-grade intervention," Greetham said - during the first 12 weeks of the study, and were administered either placebo or Naltrexone Depot. Released data show those patients treated with Naltrexone Depot and therapy had a greater likelihood of total abstinence. At six months, patients receiving the treatment were about four times as likely not to drink heavily and about eight times more likely to avoid alcohol altogether than those receiving placebo and therapy. The "p" value for both arms was 0.003.
"We were blown away," Greetham told BioWorld Today. "We thought we'd get [good "p" values] but not to that extent."
The company has discussed the product with the FDA, which wants long-term safety data. Hayward, Calif.-based DrugAbuse Sciences is planning a second Phase III trial of similar size. If all goes well, the company could approach the FDA with a regulatory package in 2004, she said.
Naltrexone binds competitively at opiate receptor sites in the brain, although its precise mechanism of action in alcoholism treatment is not known. The oral form is approved in the U.S. to treat alcohol dependence when used in combination with a comprehensive treatment program, but the knock against that formulation has been the difficulty of getting addicts, who can find relief from the throes of addiction just as easily from a bottle of booze, to take it consistently.
"It has not been particularly successful in the commercial world because addicts are notorious for not taking their medication," Greetham said. "For a long time, physicians have been asking for a sustaining formulation."
Enter Naltrexone Depot. The product, Greetham said, is designed to be given once a month by injection, thus ensuring the patient receives more than a day's benefit from the drug. DrugAbuse Sciences also is studying the product in heroin addicts.
DAS-431, a D1 receptor agonist, also in DrugAbuse Sciences' pipeline, is in a Phase IIa trial for cocaine abuse, although Greetham said it might have applications in Parkinson's disease, Huntington's disease and schizophrenia. The company is planning a schizophrenia trial for sometime this year. It also has preclinical programs in cocaine and heroin.
At the top of the list right now, though, is Naltrexone Depot. DrugAbuse Sciences would like to partner the drug and is in early discussions with companies, and should have a deal signed this year, Greetham said.