Poly (ADP-Ribose) Polymerase Inhibition for Chemotherapy-Induced Peripheral Neuropathy: A Meta-Analysis of Placebo-Controlled Trials

Background: Chemotherapy-induced peripheral neuropathy is characterized by pain, numbness, and tingling in the hands and feet and by diminished quality of life. Multiple previous studies, mostly preclinical, suggest that poly (ADP-ribose) polymerase (PARP) inhibitors may help with these symptoms. Objective: To assess the relationship between PARP inhibition and prevention/palliation of peripheral neuropathy in a clinical setting. Design: Meta-Analysis of placebo-controlled clinical trials with PARP inhibitors. Setting/Subjects: We conducted 9 literature searches that included PubMed and other sources to compile fully published placebo-controlled clinical trials that tested PARP inhibitors and that reported on peripheral neuropathy. Measurements: The relative risks for neuropathy of all grades based on PARP inhibition were calculated for each trial. Each trial was weighted by its respective sample size. A forest plot was constructed. Results: Five trials, inclusive of 843 patients, met this study's eligibility criteria. Four included a concomitant PARP inhibitor (either olaparib or veliparib) and paclitaxel, a neuropathy-causing chemotherapy agent; the remaining trial evaluated long-Term monotherapy with olaparib. The pooled overall relative risk for the development of neuropathy with PARP inhibition was 1.06 (95% confidence interval: 1-1.4). Conclusions: PARP inhibition does not appear to reduce the risk of chemotherapy-induced peripheral neuropathy. Whether PARP inhibitors may palliate (rather than prevent) neuropathy remains an area in need of further investigation.