Dr. Reddy's challenges AstraZeneca's NEXIUM

AstraZeneca confirmed on July 15, 2004 that Indian drugmaker Dr. Reddy's Laboratories had made a Hatch-Waxman filing relating to NEXIUM in the United States (presumably the first step to manufacturing a generic challenger to the branded drug NEXIUM), but that it was confident of defending a patent challenge to its top-selling ulcer drug NEXIUM (esomeprazole) after the threat of a generic competitor knocked down the value of its shares.

The interrelationship of NEXIUM and PRILOSEC is one of enantiomer to racemate, so that this paragraph IV filing may be a challenge to patent validity, and, if so, may be quite significant to many pharmaceutical patents.