August 13, 2008

Alkermes and Cephalon

The FDA has warned of the risk of injection site reactions to Vivitrol, a once-monthly injection drug for the treatment of alcohol dependence. However, due to the considerable adverse health consequences related to alcohol dependence, along with the limited number of prescription drugs available, Datamonitor does not expect Vivitrol to experience a substantial downturn in sales.

Vivitrol (extended release naltrexone from Alkermes/Cephalon), an opioid antagonist launched in June 2006 for the treatment of alcohol dependence, is the only once-monthly intramuscular medication available for the treatment of this disorder. The FDA has notified healthcare professionals of the risk of adverse injection site reactions in patients receiving the treatment. The agency has received 196 reports of injection site reactions, including cellulitis, induration, hematoma, abscess, sterile abscess, and necrosis. Sixteen patients required surgical intervention, ranging from incision and drainage to extensive surgical debridement.

Alcohol dependence is a maladaptive pattern of alcohol use leading to clinically significant impairment or distress. Excessive intake of alcohol is partly responsible for several conditions including: cirrhosis; mouth, oropharyngeal, esophageal, liver and breast cancers; and hemorrhagic stroke. As a chronic and progressive disease, which is the third leading cause of preventable death in the US, alcohol dependence carries a high socioeconomic impact. Datamonitor estimates that alcohol dependence affected 19.8 million individuals across the seven major markets in 2007.

At present, the alcohol dependence prescription drug market is greatly underserved, with the four currently marketed products receiving only a modest uptake, achieving total sales of just $86m across the seven major markets in 2006. While three of these treatments are daily oral therapies (Antabuse, ReVia (oral naltrexone) and Campral), Vivitrol's once monthly intramuscular injection relieves patients of the burden of daily compliance.

Due to the considerable adverse health consequences related to alcohol dependence and the limited number of prescription drugs available, Datamonitor does not expect the FDA's warning to cause a substantial downturn in sales of Vivitrol, which are forecast to reach $128m by 2016. However, the warning is likely to cause doctors to be more cautious in their administration of the drug, and to encourage their patients to monitor the injection site.

In addition Datamonitor believes that the current alcohol dependence pipeline is weak and lacking in innovation. Therefore none of the drugs in late-stage development are likely to outperform Vivitrol's prescription sales to 2016. However a substantial commercial potential exists for future drugs which would demonstrate greater efficacy and fewer adverse reactions than Vivitrol.