Japan's Otsuka sues U.S. FDA over Abilify in unique focus on exclusivity rules

Japan's Otsuka Pharmaceuticals accused the U.S. FDA in a unique court suit of manipulating its regulatory procedures to kill off its 7-year exclusivity to market Abilify (aripiprazole) for treating Tourette syndrome in children.

Under normal circumstances, a drugmaker wants as broad an indication or as many of them as possible to widen the scope of possible sales. In this case, Otsuka wants to keep its narrow, pediatric indication.

Otsuka filed the suit in a federal district court, which could issue an injunction soon, seeking to reverse the FDA's action, which the Japan-based company called "arbitrary, capricious and unlawful abuse of its authority." Up to $45.5 billion could be hanging on the suit's outcome.

Otsuka obtained 7-year exclusivity to market Abilify in December under the FDA's orphan drug procedures, based on the Tourette pediatric indication. Up to now, Abilify had been earning Otsuka $6.5 billion a year as one of the leading antipsychotic drugs, including treatment for bipolar disorder and schizophrenia.

In an almost Kafkaesque twist and why Otsuka is upset, Abilify's patent protection is set to expire April 20, opening it to generic competition. The orphan drug approval for treating Tourette's was Otsuka's way of keeping Abilify on the market as well as its new indication for an additional 7 years without a generic challenge.

That is what Otsuka saw as the drug's near future until February, when the agency added what Otsuka might consider a Machiavellian twist. Apparently, the FDA stepped in and decided to lift the restriction of the new indication to pediatric use and give it a new indication for treating Tourette's at all ages. That had the effect, Otsuka argued in its suit, of eliminating the 7-year exclusivity intended for pediatric use, and thus opening that indication to generic competition next month.

The argument Otsuka laid out in the suit and what the court must determine is whether the agency can approve Abilify for a broader segment of the population when no clinical trials have been conducted to test its safety and effectiveness in treating Tourette's in those age groups.

Both sides reserved their comments for the courts.

- here are the stories from Law 360 and the Wall Street Journal
- here's the release