Cephalon, a US-based drug maker, has filed a lawsuit against Lupin Ltd and its US subsidiary Lupin Pharmaceuticals for challenging the patents on its sleep disorder drug Nuvigil (armodafinil). The lawsuit is based upon an Abbreviated New Drug Application filed by Lupin, seeking approval from the US Food and Drug Administration for a generic equivalent of armodafinil to be sold in that market.
The suit was filed in the US District Court in Delaware last week. Patent experts said the product was approved in 2007 and had patent validity till 2024. Cephalon earlier sued companies such as Watson Pharma, Mylan and Teva for infringing the patent rights of some versions of this drug, which has a combined turnover of over $1 billion in the US.
Nuvigil is a longer-lasting form of a similar drug Modafinil and was launched in the United States in June 2009.
It is indicated to improve wakefulness in patients with excessive sleepiness, associated with treated obstructive sleep apnea, and shift work sleep disorder.
Cephalon has also an improved version of this drug, Nuvigil, for jet lag disorder. It occurs when a person's internal body clock becomes disrupted as a result of quick travel across several time zones.
A Lupin spokesperson declined to comment.
Last October, Teva Women's Health filed a suit against Lupin in the US District Court for the District of New Jersey, for challenging the patents of its brand Seasonale, an oral contraceptive that limits the number of menstrual periods women have in a year. A month before that, Lupin was also sued in the US District Court of Delaware by Puerto Rican drug maker Warner Chilcott for alleged infringement of patents relating to oral contraceptive brands Losetrin Fe and Fencon Fe.
Such suits, meant to delay the entry of generic medicines, are common in the US. According to the US laws for generics, the patent holder has to sue the generic player for filing patent challenge ANDAs within 45 days, to automatically trigger a 30-month stay on such approvals.
