Introduction: Pemetrexed is a pharmacotherapeutic cornerstone in the treatment of non-small cell lung cancer. As it is primarily eliminated by renal excretion, adequate renal function is essential to prevent toxic exposure. There is growing evidence for the nephrotoxic potential of pemetrexed, which even becomes a greater issue now combined immuno-chemotherapy prolongs survival. Therefore, the aim of this study was to describe the incidence of nephrotoxicity and related treatment consequences during pemetrexed-based treatment. Methods: A retrospective cohort study was conducted in the Jeroen Bosch Hospital, Den Bosch, the Netherlands. All patients that received at least 1 cycle of pemetrexed based therapy were included in the dataset. The primary outcome was defined as a ≥25 % reduction in eGFR. Additionally, the treatment consequences of decreased renal function were assessed. Logistic regression was used to identify risk factors for nephrotoxicity during treatment with pemetrexed. Results: Of the 359 patients included in this analysis, 21 % patients had a clinically relevant decline in renal function after treatment and 8.1 % of patients discontinued treatment due to nephrotoxicity. Cumulative dose (≥10 cycles of pemetrexed based therapy) was identified as a risk factor for the primary outcome measure . Conclusion:This study shows that patients on pemetrexed-based treatment are at risk of developing renal impairment. Risk significantly increases with prolonged treatment. Renal impairment is expected to become an even greater issue now that pemetrexed-based immuno-chemotherapy results in longer survival and thus longer treatment duration.

Abstract:In this report we describe a 53-year-old woman with advanced non-small cell lung cancer, treated with pemetrexed and cisplatin combination therapy, followed by pemetrexed monotherapy. The patient developed severe muscle spasms at least twice, shortly after administration of pemetrexed monotherapy. A possible explanation for this observation is that in combination with cisplatin therapy, the patient was hyperhydrated before administration to promote renal excretion and reduce toxicity. Pemetrexed is also renally excreted, which supports the finding that toxicity did not occur when the patient was hyperhydrated. After discontinuation of pemetrexed the symptoms did not reoccur. All aspects of this case point to a possible relationship between pemetrexed and an adverse drug reaction (ADR). We conclude that muscle spasms are a rare, but possibly dose-related ADR of pemetrexed-based therapy.