Background: Vinflunine is a novel vinca alkaloid with promising single agent clinical activity. Pemetrexed has at least additive activity with other vincas. A phase I trial was undertaken to assess the safety of vinflunine and pemetrexed in patients with refractory solid tumors.
Methods: A standard 3-patient cohort dose escalation scheme was used to determine the dose-limiting toxicity (DLT) and maximum tolerated dose (MTD) of the vinflunine/pemetrexed combination. Pemetrexed 500 mg/m(2) was given with vinflunine 280 mg/m(2) (cohort 1), 300 mg/m(2) (cohort 2) or 320 mg/m(2) (cohort 3) on day 1 of a 21-day cycle.
Results: 19 patients were enrolled, median age 58 years (range 32 to 77) and had a median of 3 (range 1-6) prior therapies. DLT occurred 1 of 6 pts in cohort 1 (thrombocytopenia, hyponatremia), 2 of 10 pts in cohort 2 (febrile neutropenia, hyponatremia, hyperbilirubinema; febrile neutropenia), and 2 of 3 pts in cohort 3 (febrile neutropenia, hypokalemia; febrile neutropenia). 1 pt in cohort 2 died prior to completion of cycle 1 likely from disease progression. Most common grade 3/4 adverse events were neutropenia (7), leukopenia (5). Febrile neutropenia occurred in 4 patients (21%). No objective responses were seen. Two patients (breast and lung) had prolonged stable disease for 25 and 20 cycles respectively.
Conclusions: Based on this experience we recommend vinflunine 300 mg/m(2) and pemetrexed 500 mg/m(2) in combination every 3 weeks for future study. At these doses, the combination of vinflunine and pemetrexed was tolerable in this heavily pretreated population. Hematologic toxicity, including febrile neutropenia, was prominent.