- Second-line chemotherapy with pemetrexed after gemcitabine failure in patients with advanced pancreatic cancer: a multicenter phase II trial. Boeck, S., Weigang-Köhler, K., Fuchs, M., Kettner, E., Quietzsch, D., Trojan, J., Stötzer, O., Zeuzem, S., Lordick, F., Köhne, C.H., Kröning, H., Steinmetz, T., Depenbrock, H., Heinemann, V. Ann. Oncol. (2007)