UTC Says Liquidia Can’t Void Key Claim From Lung-Drug Patent

United Therapeutics Corp. urged a Delaware judge to reject Liquidia Corp.'s bid to invalidate a key patent claim for UTC’s Tyvaso lung-disease drug, arguing its rival relies on evidence that can’t be used for that purpose.

The patent that Liquidia says renders Claim 14 in UTC’s US Patent No. 11,826,327 invalid as obvious can’t be cited as prior art because it was also developed by UTC, according to a brief filed Thursday in the US District Court for the District of Delaware.

Liquidia conceded at the start of the trial that its Yutrepia infringes Claims 1 and 14, leaving only ...