Novartis’ generic subsidiary Sandoz has failed in a bid to block the launch of two copycat versions of Merck & Co’s blockbuster cholesterol drug Zocor until an ongoing legal dispute about exclusivity rights has been resolved.

Sandoz had asked a US district court to issue a preliminary injunction against the launch of Zocor (simvastatin) generics from Teva and Ranbaxy, which were approved by the FDA towards the end of June.

The FDA approval allowed both companies to share six months’ exclusivity in the marketplace for generic forms of Zocor, which had sales of more than $3 billion last year. The agency had initially turned down their request for exclusivity under the first-to-file laws in the USA, saying that all generic manufacturers should be allowed to enter the marketplace at the same time, but was overruled in the courts.

Sandoz, which also wants to launch generic Zocor, wanted the introduction of any generic delayed until the outcome of an FDA appeal against court decision that is due to be heard later this year.

The judge in the latest case said granting the injunction would prevent low-dost simvastatin reaching the marketplace on schedule and remove an opportunity for savings for consumers and healthcare payers.

Meanwhile, Merck has taken the unusual move off cutting its own deal with a major US insurance company to offer Zocor at a price below the copycat versions in order to restrict the impact of generic competition on the franchise.