A poly (ADP-ribose) polymerase (PARP) inhibitor, Olaparib has shown notable clinical effectiveness in treating metastatic castration-resistant prostate cancer (mCRPC) with DNA damage repair gene mutations. Though initial reactions were encouraging, the emergence of resistance poses a major clinical problem that reduces the long-term therapeutic value for patients. This paper thoroughly investigates the molecular processes behind acquired and intrinsic resistance to Olaparib in prostate cancer (PCa). Among the several resistance routes discovered are restoration of homologous recombination (HR) repair capacity via secondary BRCA2 mutations, loss of 53BP1/REV7/Shieldin complex activity, and activation of alternative DNA repair pathways. Recent studies further imply that changes in cell cycle checkpoints and epigenetic changes could help to increase therapy resistance even more. Knowing these several resistance mechanisms helps one to create reasonable combination strategies and biomarker-driven initiatives to defeat Olaparib resistance. Among the new treatment options are combination therapies aimed at compensatory DNA repair mechanisms, cell cycle checkpoint inhibitors, epigenetic modulators, and methods tackling tumor microenvironment elements. Predictive biomarker discovery of resistance will help to guide individual treatment choice and sequential therapy optimization, hence changing clinical results for advanced PCa patients in the precision medicine age.
Keywords: Olaparib; PARP inhibitor; Prostate cancer; Therapy; mCRPC.
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