Sanofi moves to block Wockhardt patent challenge

Battle in US court on anti-allergic drug Allegra.

Sanofi-Aventis, the world’s third largest drug maker, has approached a US court against Wockhardt for challenging the patents of Allegra (fexofenadine hydrochloride), one of the largest selling anti-allergic drugs in the world.

According to the petition filed by the patent-holders and licensees — Sanofi-Aventis US, Aventisub II and Carderm Capital — in the US District Court of New Jersey on March 18, Wockhardt’s revised marketing application in February (abbreviated new drug application or Anda) infringes five patents associated with Allegra.

These patents are related to the 30 mg, 60 mg and 180 mg formulations of Allegra and 60 mg of Allegra D-12 hour-extended release capsules. In November 2007, Wockhardt withdrew its Paragraph IV Anda filed with the US drug regulator for the marketing rights of Allegra and converted these into Paragraph III applications. While Para III applications are to notify not-to-challenge patents and wait till the product gets off-patent for launch, Para IV specifies that the generic company is challenging the patents of the innovator to launch its product before patent expiry.

“We have a strong case and can overcome the current challenges on the patents relating to Allegra,” said a Wockhardt spokesperson.

Allegra is one of Sanofi-Aventis' largest selling drugs and had peak sales of over $1.5 billion for its various versions. The patent for the main compound of Allegra had expired in 2001, but Sanofi-Aventis has various tweaked versions of the drug with patent protections lasting up to 2014, said experts.

“Wockhardt is unlikely to gain a major windfall from the patent challenge of Allegra now, as already companies like Teva, Mylan and Dr Reddy's Laboratories have approval for Allegra, and Ranbaxy and Sandoz have tentative approvals,” said Ranjit Kapadia, Vice President-Institutional Research at HDFC Securities.

Albany Molecular Research Inc (Amri) and Sanofi-Aventis had sought a preliminary injunction last week in the same court against Dr Reddy's Laboratories from distributing a generic of Allegra D-24, following Dr Reddy's getting final approval for marketing. In September 2009, Amri had filed a patent infringement lawsuit in the US District Court for New Jersey against Dr Reddy’s for infringement of one of its patents related to the manufacturing process for the active ingredient in Allegra, Allegra-D12, and Allegra-D 24.

Such litigation is common in the US between innovator companies and generic players who make cheap versions of the drug through different processes. According to the US rules for selling generic drugs, an innovator has to sue a patent challenger within 45 days of receiving the notification of a patent challenge, to prevent the drug regulator from approving the drug for the next 30 months, before the patent expiry or till a court gives its judgment.