Thanks to the drug-delivery technology of biotech Alkermes (NASDAQ:ALKS), a 20-year-old drug is about to get a new lease on life. On the basis of a very successful phase 3 study, Alkermes has filed for approval from the Food and Drug Administration for its long-acting injectable formulation of Vivitrex (naltrexone) for the treatment of alcoholism.

In a large phase 3 study -- large by the standards of prior alcoholism studies -- monthly injections of Vivitrex were shown to reduce heavy-drinking days from an average of 19 per month to just three. What's especially interesting is that this trial, unlike most other alcoholism studies, did not require patients to quit drinking before beginning the study -- in fact, more than 90% of the patients enrolled in the study were actively drinking at the time of enrollment.

For those interested in a little more background, naltrexone was first used in treating heroin addiction, back in the early '80s. Approved for the treatment of alcoholism in 1994, the pill form of the drug has generally never really taken off because many patients don't like to take the pills every day.

This injected form of Vivitrex should be better for patients, since taking pills every day is replaced by a monthly injection from a doctor. Not only that, but the side-effect profile -- nausea, headache, and fatigue -- also seems quite acceptable and, ironically, rather similar to the side effects of drinking too much.

For Alkermes investors, Vivitrex has been something of a saga. Not only was the filing delayed from initial expectations, but the company still has not signed up a marketing partner. Although certainly frustrating to investors who'd no doubt like to see the stock pop on such an announcement, holding out for a good deal might prove to be a good move in the long run for Alkermes -- particularly since marketing and detailing could be unusually import for this drug.

Of course, none of this is to suggest that Alkermes is a one-trick pony. The company's long-acting antipsychotic drug Risperdal Consta is marketed by Johnson & Johnson (NYSE:JNJ), and the company has two ongoing partnerships in diabetes -- one for a long-acting version of Amylin Pharmaceuticals' (NASDAQ:AMLN) exenatide, and a second for inhaled insulin, called AIR Insulin. Both diabetes treatments also have Eli Lilly (NYSE:LLY) as a partner.

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Fool contributor Stephen Simpson owns shares of Johnson & Johnson and Amylin Pharmaceuticals. The Motley Fool has a disclosure policy.