Background: Non-small cell lung cancer (NSCLC) has undergone a major change in the last decade in terms of survival and prognosis due to the introduction of new drugs in the last 10 years. One of the drugs with the most promising preliminary results in NSCLC are PARP inhibitors (iPARPs), whose clinical trials have very heterogeneous results. The use of iPARPs in NSCLC may lead to increased survival in several selected patients, and their use may become a standard in the coming years. However, there is currently controversy about the efficacy and safety of these drugs in NSCLC. Therefore, future studies are needed to evaluate their role in these tumours. The aim of this review is to evaluate the efficacy and safety of iPARPs in the treatment of NSCLC.
Methods: We performed a systematic review with meta-analysis using the different clinical trials (PubMed, COCHRANE, Science Direct, EMBASE and the clinical trial registry) that evaluated the efficacy and safety of iPARP in NSCLC by PRISMA criteria. The primary endpoint was to evaluate the efficacy of iPARPs in the treatment of NSCLC through overall and progression-free survival (OS and PFS). Two authors independently reviewed the articles and abstracts (A.O.H. and J.R.R.), with subsequent confirmation by a third independent reviewer (E.B.M.). The heterogeneity of the included studies in the meta-analysis was assessed by using the I2 statistic.
Results: A total of 14 articles were included for analysis (2,651 patients). A total of 1,503 patients were randomised in iPARP arms and 1,148 patients were included in control arms. Three clinical trials were conducted in localised or locally advanced NSCLC and 11 in advanced or metastatic stages. The global OS of the meta-analysis showed a hazard ratio (HR) of 0.85 [95% confidence interval (CI): 0.74-0.97] with a heterogeneity (I2) of 0% (P=0.84). PFS showed a HR of 0.93 (95% CI: 0.74-1.17) with an I2=51% (P=0.07). The overall adverse event rate (grade 1-5) was similar in both iPARP and placebo arms.
Conclusions: iPARPs are a future promising in the treatment of NSCLC in terms of efficacy and safety. Proper patient selection [homologous recombination deficiency (HRD) positive] is key for future clinical trials. The studies conducted to date open a new approach for a novel treatment modality in NSCLC.
Keywords: Non-small cell lung cancer (NSCLC); PARP inhibitor (iPARP); biomarker; homologous recombination deficiency (HRD); systematic review.