Study of DNA Damage, Angiogenesis, and PD-L1 Inhibitors in Advanced Solid Tumors

Durvalumab is a human immunoglobulin G (IgG)1 kappa monoclonal antibody directed against human PD-L1. Durvalumab selectively binds human PD-L1 with high affinity and blocks its ability to bind to PD-1 and cluster of differentiation (CD)80. The fragment crystallizable (Fc) domain of durvalumab contains a triple mutation in the constant domain of the IgG1 heavy chain that reduces binding to the complement component C1q and the Fc gamma receptors responsible for mediating antibody dependent cell mediated cytotoxicity.

Olaparib (AZD2281) is a potent oral poly Poly (ADP-ribose) Polymerase (PARP) enzyme inhibitor (PARP-1, -2 and -3) that is being developed as an oral therapy, both as a monotherapy (including maintenance) and for combination with chemotherapy and other anti-cancer agents. Olaparib specifically traps PARP1 and PARP2 enzymes at sites of damaged DNA; the trapped PARP1- or PARP2-DNA complex is cytotoxic and produces clinical response. Although olaparib also binds to PARP3, recent investigations have suggested PARP-3 inhibition does not contribute towards anti-cancer activity.

Cediranib (AZD2171) is a potent oral small molecule Vascular Endothelial Growth Factor (VEGF) receptor tyrosine kinase inhibitor, specifically inhibiting all three VEGF receptors (VEGFR-1, -2 and -3). It has additional inhibitory activity against stem cell factor receptor tyrosine kinase, and less potency against platelet-derived growth factor receptor tyrosine kinases. Cediranib exerts its anti-angiogenic property by competitively inhibiting the ATP binding site on the VEGF receptors.