Effect of renin-angiotensin system inhibitors on pemetrexed plus platinum-induced hematological toxicities: A multicenter retrospective study using three propensity score analyses

Hematological toxicities induced by pemetrexed plus platinum therapy remain a critical issue in clinical practice. We hypothesized that inhibition of the renin-angiotensin system (RAS) can ameliorate pemetrexed-induced hematological toxicities through drug-drug interactions involving organic anion transporters. Thus, this study aimed to clarify whether RAS inhibitors (RASIs) could prevent pemetrexed plus platinum-induced hematological toxicities. We retrospectively analyzed data from 305 consecutive patients with non-small cell lung cancer or malignant pleural mesothelioma who received their first cycle of a pemetrexed plus platinum regimen and were treated with or without RASIs. The primary endpoint was the incidence of severe myelosuppression after the first cycle. Propensity score (PS)-matched, PS-adjusted, and inverse probability of treatment weighting (IPTW) analyses were used. The number of patients with grade ≥3 hematological toxicities was 27 (8.9%). PS-matched analyses revealed that the concomitant use of RASIs was slightly associated with a lower risk of grade ≥3 hematological toxicities (odds ratio [OR], 0.68; 95% confidence interval [CI], 0.20-2.32; p = 0.536). Additionally, sensitivity analyses using PS-adjusted and IPTW methods demonstrated similar results (OR, 0.63; 95% CI, 0.19-2.15; p = 0.463 and OR, 0.37; 95% CI, 0.11-1.29; p = 0.117, respectively). These findings suggest that RASIs might prevent pemetrexed plus platinum-induced hematological toxicities.