AstraZeneca said Tuesday that India’s biggest drug maker, Ranbaxy Laboratories, has filed an Abbreviated New Drug Application (ANDA) with the FDA to make its own version of the ulcer treatment Nexium (esomeprazole magnesium delayed-release capsules).
Nexium is AstraZeneca’s top seller, bringing in $3.8 billion in revenue in 2004.
AstraZeneca is already fighting a challenge to Nexium from Indian generic drug maker Dr. Reddy’s Laboratories.
AstraZeneca has 45 days within which to commence a patent infringement lawsuit against Ranbaxy that would automatically stay, or bar, the FDA from approving Ranbaxy’s ANDA for 30 months or until a court decision, whichever comes first.