New Delhi: New York-listed Dr Reddy’s Laboratories Ltd (DRL) on Wednesday got the US drug regulator’s final nod to sell its generic version of Sanofi Aventis SA’s anti-allergic drug Allegra D-24.

The company plans to launch it in the first quarter of 2011. The launch will be a so-called at-risk launch for DRL since the patent litigation over the drug between DRL and Sanofi is still unresolved.

“We got approval to launch Allegra D-24 since the 30-month stay on the approval following the patent case filing by Sanofi is now over,” a DRL spokesperson said. “We also believe that we are the only ones to have filed with the FDA (US Food and Drug Administration) to launch the generic version of this drug.”

Analysts say that since DRL may be the only company to have filed a generic drug approval application, this would be an extended exclusivity opportunity for the company for at least three years.

“We believe this could add approximately $150 million to earnings over this period,” stated a Citi Investment Research report.

However, an at-risk launch would mean that if DRL loses the patent litigation, it will have to pay damages to Sanofi.

But according to the Citi report, “DRL is comfortable with an at-risk launch, as Allegra D-24 is covered by the same patents that cover Allegra, which it has already launched a few years back.”

Allegra D-24 has sales worth $200 million in the US. DRL also has the FDA’s tentative approval for Allegra D-12. The final approval is expected in November.

Shares of DRL fell 0.2% to Rs1,227.35 on a day when the benchmark Sensex index on the Bombay Stock Exchange rose 0.2% to close at 17,519.26.

radhieka.p@livemint.com