Gilead charges Merck attorney with lying

A federal judge has reopened a patent suit between Gilead Sciences and Merck & Co. after evidence turned up suggesting a Merck patent attorney lied.

In late March, a federal jury in California ordered Gilead, maker of the hepatitis C drugs Sovaldi and Harvoni, to pay $200 million for patent infringement. The dispute centered on an active ingredient in both drugs, sofosbuvir, which Gilead acquired from Pharmasset. Merck contended that Pharmasset derived the chemical from a Merck patent.

Now that $200 million payment is at risk. Gilead is arguing before a federal judge that a Merck attorney hid the fact that he had been involved in a conference call with Pharmasset employees in 2004 when Merck had tried to license patents that ultimately led to sofosbuvir. Merck failed in the licensing attempt, and Gilead bought Pharmasset and its hepatitis C drugs in 2011 for $11 billion.

However, during the call, the Merck attorney, Philippe Durette, who is also a chemist, learned the structure of a Pharmasset experimental drug, Gilead contends. Merck then used the knowledge gained by Durette to file its own patent applications so that they would cover Pharmasset’s drug. Merck won approval for its own hepatitis C drug, Zepatier, earlier this year.

Merck said in a court document that Durette didn’t initially remember the call. Nonetheless he acted properly, Merck insists, because he didn’t update Merck’s patents until after Pharmasset published the structure of its experimental drug.

But Gilead maintains in a court document that, “simply put, Merck’s asserted patents claim work Merck never did and ideas Merck never had. The asserted claims are invalid, and Merck should collect nothing.”