At last week's FDA patient-focused drug development meeting, pulmonary arterial hypertension patients credited marketed vasodilators with saving their lives, but said dyspnea and fatigue are still crippling. Clinicians say targeting the underlying inflammatory and fibrotic elements of the disease could help ameliorate those two key symptoms.

The message has not been lost on industry, as a handful of molecules are in early stage clinical development that could address some of the other elements of PAH.