PMID: 26222319

Authors:

Papeo GM, Posteri H, Borghi D, Busel AA, Caprera F, Casale E, Ciomei M, Cirla A, Corti E, D'Anello M, Fasolini M, Forte B, Galvani A, Isacchi A, Khvat A, Krasavin MY, Lupi R, Orsini P, Perego R, Pesenti E, Pezzetta D, Rainoldi S, Riccardi-Sirtori F, Scolaro A, Sola F, Zuccotto F, Felder ER, Donati D, Montagnoli A

Title:

Discovery of 2-[1-(4,4-difluorocyclohexyl)piperidin-4-yl]-6-fluoro-3-oxo-2,3-dihydro-1H-isoind ole-4-carboxamide (NMS-P118): a Potent, Orally Available and Highly Selective PARP-1 Inhibitor for Cancer Therapy.

Journal:

J Med Chem. 2015 Jul 29.

Abstract:

The nuclear protein poly(ADP-ribose) polymerase-1 (PARP-1) has a well-established role in the signaling and repair of DNA and is a prominent target in oncology, as testified by the number of candidates in clinical testing. However all current compounds unselectively target both PARP-1 and its closest isoform PARP-2. The goal of our program was to find a PARP-1 selective inhibitor that would potentially mitigate toxicities arising from cross-inhibition of PARP-2. Thus, an HTS campaign on the proprietary Nerviano Medical Sciences (NMS) chemical collection, followed by SAR optimization around the unselective isoindolinone-4-carboxamide hits 10a and 10b, allowed us to subsequently discover 2-[1-(4,4-difluorocyclohexyl)piperidin-4-yl]-6-fluoro-3-oxo-2,3-dihydro-1H-isoind ole-4-carboxamide (NMS-P118, 20by). NMS-P118 proved to be a potent, orally available and highly selective PARP-1 inhibitor endowed with excellent ADME and pharmacokinetic profiles and high efficacy in vivo both as a single agent and in combination with temozolomide, in MDA-MB-436 and CAPAN-1 xenograft models, respectively. High resolution X-ray diffraction co-crystal structures of 20by with both PARP-1 and PARP-2 catalytic domain proteins allowed rationalization of the observed selectivity.