On November 15, 2018, biotechnology companies Arena Pharmaceuticals and United Therapeutics announced that they have entered into a global license agreement for Arena's Phase 3 investigational drug candidate, ralinepag, a next-generation, oral, selective, and potent prostacyclin receptor agonist in development for the treatment of pulmonary arterial hypertension (PAH). Wilson Sonsini Goodrich & Rosati is representing United Therapeutics in the transaction.

Under the terms of the agreement, Arena will grant United Therapeutics exclusive, worldwide rights to develop, manufacture, and commercialize ralinepag. In return, Arena will receive up to $1.2 billion, including an upfront payment of $800 million and potential milestone payments totaling up to $400 million based on the achievement of certain regulatory events. Additionally, Arena will receive low double-digit tiered royalties on annual net sales of ralinepag.

The Wilson Sonsini team representing United Therapeutics in the transaction includes partners James Clessuras, Mark Holloway, Robert Ishii, Michael Hostetler, and associate Barath Chari.

For more information, please see the companies' joint press release.