Barr sues FDA

US company Barr Pharmaceuticals is suing America's Food and Drug Administration (FDA) because it claims the US regulator is set to force it to share its six-month exclusivity period for a generic version of popular anti-allergy drug Allegra-D with another company.

Barr said its subsidiary, Barr Laboratories, was challenging the FDA's practice of awarding the 180-day incentive on a ìpatent-by-patentî basis, rather than solely to the first company to submit an application challenging an existing patent.

Under federal law, such exclusivity time is generally granted to companies filing the first challenge, as a reward for bringing low-cost versions to the market quickly.

Barr says it filed to market a generic version of the sanofi-aventis drug in September 2001. However Aventis (as it was then known) listed another patent for Allegra-D the following year and Barr fears that the FDA may conclude that another generic company, Impax Laboratories, will be due some exclusivity as it filed the first challenge on the later patent.

Under a 1984 law (Hatch-Waxman), which was enacted to encourage competition within the industry, Barr insists it is due the rights to sole exclusivity.

ìWe believe that the exclusivity provisions of Hatch-Waxman are clear and that the first company to file a patent challenge is entitled to the 180-day incentive,î said Barr CEO, Bruce Downey. ìWe will seek all remedies to ensure thatÖgeneric exclusivity is preserved as Congress intended.î

Sanofi-aventis contends that no generic company should be allowed to promote to sell other versions of its drugs, regardless of the outcome of the Barr lawsuit.

ìGeneric versions of Allegra-D cannot be marketed as we hold multiple enforceable patents that do not expire until between 2012 and 2019,î said Sanofi-aventis US spokeswoman Melissa Feltmann.

An FDA spokesman said it was not the agency's policy to comment on ongoing litigation.

Barr won tentative approval to market Allegra-D in July 2004, once its challenge to the Aventis patent had been approved on a preliminary basis. Should the firm win its current battle, the drug could prove to be very lucrative; in the twelve months up to November 2004 it amassed sales of $444m, according to IMS data.

Barr was the first drug manufacturer to sell a generic version of Prozac.