Delta-like ligand 4 inhibitor drug treatment induces pulmonary hypertension in cancer clinical trials.

Delta-like ligand 4 (DLL-4) inhibitor drugs are an emerging cancer treatment. In clinical trials for solid organ malignancies, intravenous administration of monoclonal antibodies that inhibit DLL-4 is associated with development of pulmonary hypertension, in the absence of left ventricular dysfunction. Analysis of 13 clinical trials showed that pulmonary hypertension is a complication of DLL-4 inhibition.

NOTCH3 and Pulmonary Arterial Hypertension.

NOTCH3 receptor signaling has been linked to the regulation of smooth muscle cell proliferation and the maintenance of smooth muscle cells in an undifferentiated state. Pulmonary arterial hypertension (World Health Organization Group 1 idiopathic disease: PAH) is a fatal disease characterized clinically by elevated pulmonary vascular resistance caused by extensive vascular smooth muscle cell proliferation, perivascular inflammation, and asymmetric neointimal hyperplasia in precapillary pulmonary arteries. In this review, a detailed overview of the specific role of NOTCH3 signaling in PAH, including its mechanisms of activation by a select ligand, downstream signaling effectors, and physiologic effects within the pulmonary vascular tree, is provided.