A Phase I Open-Label Dose-Escalation Study of Intravenous BI 2536 Together With Pemetrexed in Previously Treated Patients With Non–Small-Cell Lung Cancer

IntroductionBI 2536 is a potent, highly selective inhibitor of polo-like kinase (Plk) 1. This open-label, phase I study investigated the maximum tolerated dose (MTD), safety, efficacy, and pharmacokinetics (PK) of BI 2536 IV in combination with standard-dose pemetrexed in previously treated advanced or metastatic non–small-cell lung cancer.Patients and MethodsA standard 3 + 3 design was used. The patients received 500 mg/m2 pemetrexed and escalating doses of BI 2536 on day 1 every 3 weeks. The primary objective was the MTD of BI 2536 combined with pemetrexed. Secondary endpoints were response rate (Response Evaluation Criteria in Solid Tumors), overall safety, and PK.ResultsForty-one patients received BI 2536 (100-325 mg). Two dose-limiting toxicities (DLT) occurred at BI 2536 325 mg (grade 3 pruritus and rash; grade 4 neutropenia). Therefore, the MTD for BI 2536 in combination with pemetrexed was 300 mg. After expanding the MTD dose level, 3 additional patients experienced DLTs, which resulted in expansion of the 250 mg cohort, in which 4 of the 13 additional patients experienced DLTs. Therefore, the recommended dose of BI 2536 was 200 mg. Most frequently reported drug-related adverse events were fatigue (71%), nausea (37%), and rash (34%). Two patients had durable confirmed partial responses; 21 (54%) patients had stable disease after the treatment cycle 2. PK analysis showed that BI 2536 and pemetrexed exposure were not altered when coadministered.ConclusionBI 2536 200 mg combined with standard-dose pemetrexed has an acceptable safety profile in relapsed non–small-cell lung cancer. The antitumor activity observed is encouraging and supports further investigation of Plk inhibitors.