US district court upholds ViiV HIV patent

The US District Court for the District of Delaware has upheld the validity of a GSK-held patent that covers two HIV drugs marketed in the US by ViiV Healthcare.

ViiV Healthcare is a joint venture between GSK, Shionogi and Pfizer focused on the development of HIV therapies.

US patent 6,417,191 covers HIV drugs Epzicom, a double combination of lamivudine and abacavir, and Trizivir, made of a triple combination of lamivudine, abacavir and zidovudine. It is due to expire in March 2016.

Teva sought approval from the US Food and Drug Administration to market a generic version of Epzicom, while Lupin wanted approval for a generic version of Trizivir, but ViiV argued that Teva and Lupin’s generic products would infringe the GSK patent.

In the case, Teva and Lupin argued that GSK’s patent was invalid on the grounds of obviousness. They added that the patent is invalid “due to lack of enforcement and utility”, and said their proposed generic products do not infringe the ‘191 patent.

Judge Andrews said in the opinion that the defendants had not proven by “clear and convincing evidence” that any of the asserted claims of the ‘191 patent are invalid.

ViiV failed to prove that Lupin’s generic products infringe the patent, he continued.

ViiV reacted to the opinion in a statement on its website: “ViiV Healthcare is disappointed with this component of the court’s decision and is evaluating options for next steps in the legal process.”

It told LSIPR that it intends to appeal against this part of the decision.

When contacted by LSIPR, Teva said that it had no comment.