San Diego-based Aires Pharmaceuticals, a developer of treatments for pulmonary arterial hypertension, said this morning that it has raised $20M in a Series B funding round. The round was led by MPM Capital, and also included prior investor ProQuest Investments. MPM's Dr. William Greene joins the board as part of the funding. As part of the funding, Aires said that it has entered into an agreement with Novartis, where Novartis will gain an exclusive option to acquire the firm completing successful completion of its Phase 2 clinical study of its lead compound, Aironite. The deal with Novartis could be worth as much as $250M. More information »