Dr Reddy's Laboratories has filed a lawsuit seeking declaratory judgement against American multinational Pfizer Inc, in the US District Court of New Jersey, regarding its Abbreviated New Drug Application (ANDA) for Sertraline HCI. According to a press statement from DRL, "The lawsuit seeks declararatory judgement that the claims of certain Pfizer patents are invalid and/or not infringed."

The company had filed an ANDA with the US Food and Drug Administration (US FDA) for Sertraline HCI tablets equivalent to 25, 50 and 100 mg base, with a Paragraph IV certification on four of the five patents listed on the Orange Book. Dr Reddy's notified Pfizer on the filing. Pfizer did not file a lawsuit against Dr Reddy's within the 45-day period prescribed by Hatch-Waxman Act, which governs the generic drugs in the US.

Sertraline HCI is a generic version of Pfizer's Zoloft. It is indicated for use in the treatment of major depressive disorder, obsessive-compulsive disorder, panic disorder, post-traumatic stress and pre-menstrual dysphoric disorder. The drug had sales of $2.4 billion in 2002.

As of December 31, 2002, DRL had filed 30 ANDAs with US FDA, of which 17 are paragraph IV filings. Nineteen ANDAs are currently pending approval, 14 of which are para IV filings, which address a total market value of $ 12.7 billion.