Dr. Reddy's Laboratories (DRL) has been slapped with a lawsuit for patent infringement by the US based AAI Pharma Inc for the generic version of the anti-depressant drug Prozac. DRL has a 180 days exclusivity to sell the drug's 40 mg dosage form along with Barr Laboratories that holds the exclusivity for the 10 and 20 mg dosage forms. DRL expects this to be a routine move as the para IV filing after the patent expiry allows the patent holder to file a lawsuit to challenge the generic player's entry.
AAI Pharma has 2 patents on Fluoxetine approved in July 2001 after the 180 exclusivity was granted to DRL and Barr Laboratories. Pharmaceutical Resources Inc is Dr Reddy's marketing partner for Fluoxetine in the US. Eli Lilly holds the patent holder for fluoxetine that expired in August 2001.
Dr Reddy's is not in danger of losing its exclusivity. Since DRL has already won the case against the patent holder, EIi Lilly, earlier this year, this lawsuit should be fairly easier to go through. This is the second time that DRL has suffered a setback in the past three weeks as recently Novartis withdrew from developing its licensed anti-diabetes molecule to Novo Nordisk that had been sub-licensed to Novartis.