Abstract 4198: Highly potent and selective DNA-PK inhibitor M3814 with sustainable anti-tumor activity in combination with radiotherapy

Thomas Fuchss, Werner W. Mederski, Ulrich Emde, Hans-Peter Buchstallter, Frank Zenke, Astrid Zimmermann, Christian Sirrenberg, Lubo Vassilev, Lars Damstrup, Klaus Urbahns, Andree Blaukat
2017 Cancer Research  
DNA-dependent protein kinase (DNA-PK) is a critical player in the DNA damage response (DDR) and instrumental in the non-homologous end-joining pathway (NHEJ) used to detect and repair DNA double-strand breaks (DSBs). We demonstrate that the potent and highly selective DNA-PK inhibitor, AZD7648, is an efficient sensitizer of radiation-and doxorubicininduced DNA damage, with combinations in xenograft and patient-derived xenograft (PDX) models inducing sustained regressions. Using ATM-deficient
more » ... ng ATM-deficient cells, we demonstrate that AZD7648, in combination with the PARP inhibitor olaparib, increases genomic instability, resulting in cell growth inhibition and apoptosis. AZD7648 enhanced olaparib efficacy across a range of doses and schedules in xenograft and PDX models, enabling sustained tumour regression and providing a clear rationale for its clinical investigation. Through its differentiated mechanism of action as an NHEJ inhibitor, AZD7648 complements the current armamentarium of DDR-targeted agents and has potential in combination with these agents to achieve deeper responses to current therapies.
doi:10.1158/1538-7445.am2017-4198 fatcat:ye2baonv5zb5nlhsvaeibynvzu