Influence of renal function on the clinical efficacy of carboplatin plus pemetrexed in patients with non-small cell lung cancer

Pemetrexed, a structural antifolate agent that is eliminated via renal excretion, is commonly used to treat non-squamous non-small-cell lung cancer (NS-NSCLC). Although poor renal function is associated with a high incidence of toxicities, the association of high renal function with chemotherapy efficacy and toxicity remains unknown. We aimed to investigate the effect of renal function on the efficacy and toxicity of carboplatin-pemetrexed chemotherapy in patients with NS-NSCLC. We performed a post-hoc analysis of a prospective observational study of carboplatin-pemetrexed treatment in NS-NSCLC patients. Baseline renal function was calculated using the Japanese estimated glomerular filtration rate (eGFR) formula, and the patients were then divided into two groups based on the eGFR: high-eGFR (eGFR ≥ 80 mL/min/1.73 m2, N = 162) and low-eGFR (eGFR < 80 mL/min/1.73 m2, N = 176) groups. Although the response rates in the high- and low-eGFR groups were similar (22.2% vs 23.9%, P = 0.7205), the disease control rate was significantly lower in the high-eGFR group than in the low-eGFR group (75.9% vs 84.7%, P = 0.043). Progression-free survival (PFS) and overall survival (OS) in the high-eGFR group were significantly shorter than those in the low-eGFR group (adjusted hazard ratio for PFS and OS, 1.32 [95% CI, 1.04-1.69; P = 0.0245] and 1.49 [95% CI, 1.15-1.93, P = 0.0023], respectively). The incidence of hematological and non-hematological toxicities was lower in the high-eGFR group. In conclusion, a high-eGFR is associated with poor efficacy and mild toxicity of carboplatin-pemetrexed in patients with NSCLC.