AstraZeneca's last-ditch attempt to protect its statin Crestor failed as a federal judge denied its bid for a restraining order against generic drugmakers.
Rosuvastatin, marketed as Crestor, is a class of statins, used to treat high cholesterol and related conditions, and to prevent cardiovascular disease.
AstraZeneca has seen a sharp drop in sales from the highs of 2011 because of patents expirations on top drugs.
The drugmaker had argued that the $5-billion statin should be protected with a brand-new orphan drug approval till 2026.
Petitioning the FDA last month, the company said, the agency's own policies would bar generic drug labels that did not include data on the new paediatric indication. Due to orphan drug exclusivity, that data was AstraZeneca's exclusive domain.
When the FDA failed to act on the petition, AstraZeneca took the matter to court. Following a flurry of last-minute arguments on Tuesday, Judge Randolph Moss for the District of Columbia turned down the request, according to the court docket in the case. The FDA's generic approvals were official.
Commentators say, it was a bold, though questionable bid to protect a multibillion-dollar drug from generic competition. A similar bid had been launched by Japanese pharmaceutical company Otsuka last year, when it sued to block Abilify copycats; the company's atypical antipsychotic was also approved for an orphan drug use.
With about a half-dozen generics makers gearing up to launch their produces, the fate of AstraZeneca's massive brand hangs in the balance, say commentators.
Bloomberg reported, citing stock exchange filings from India's Aurobindo Pharma Ltd, Glenmark Pharmaceuticals Ltd and Sun Pharmaceutical Industries Ltd, that they had received approval from the US FDA to sell the generics.
Other generics makers with tentative approvals are Torrent Pharmaceuticals and Alkem Laboratories.
Aurobindo Pharma said it is eligible for 180 days of "shared exclusivity" to sell the drug.
The first copycat version of Crestor, is already on the market from Allergan Plc's Watson Pharmaceuticals, after a settlement in a patent infringement suit gave the manufacturer sole rights to start selling its version in early May, the report added.
Generic drugmakers including Novartis AG unit Sandoz, Apotex and Mylan had said in court filings that they were prepared to launch generic versions of Crestor, which lost patent protection earlier this month.
Former presidential candidate and senator Bernie Sanders had slammed the company's bid to extend its exclusivity. The Democrat Senator from Vermont, along with seven Democratic Representatives had urged the US Food and Drug Administration in a 7 July letter not to let the company exploit a "loophole."
Allergan plc had already been selling generic Crestor in the US since May under a licensing agreement with AstraZeneca, and is not affected by Tuesday's order.