Purpose: PARP inhibition is an exciting new anticancer strategy. As the first PARP inhibitor approved for the treatment of advanced BRCA -mutated ovarian cancer, olaparib has proven to be effective in the treatment of several solid tumors. We performed a meta-analysis of published randomized controlled trials to evaluate the efficacy and safety of olaparib in cancer patients.
Methods: PubMed, Embase, and oncology-conference proceedings were searched for relevant studies. End points were overall survival (OS), progression-free survival (PFS), overall response rate (ORR), and grade 3/4 adverse events. Pooled hazard ratio (HR)/risk ratio (RR) and 95% CI were calculated using random or fixed-effect models.
Results: Eight trials involving 1,957 patients were ultimately identified. The pooled analysis demonstrated that olaparib treatment significantly improved PFS (HR 0.62, 95% CI 0.47–0.82; P =0.001), OS (HR 0.82, 95% CI 0.73–0.93; P =0.001), and ORR (RR 1.38, 95% CI 1.16–1.65; P <0.001) when compared with therapy not containing olaparib. This association was further confirmed by sensitivity analysis. Additionally, olaparib treatment offered a significant survival benefit for patients with BRCA  mutation. Moreover, treatment with olaparib was associated with a significant increase in risk of severe anemia.
Conclusion: Olaparib treatment has better treatment response compared with therapy not containing olaparib, whereas olaparib can increase the risk of severe anemia.
Keywords: olaparib, efficacy, safety, cancers, meta-analysis, RCTs