A comparison of clofarabine with ara-C, each in combination with daunorubicin as induction treatment in older patients with acute myeloid leukaemia by Burnett, A, Russell, N, Hills, R, Kell, J, Nielsen, O, Dennis, M, Cahalin, P, Pocock, C, Ali, S, Burns, S, Freeman, S, Milligan, D, Clark, R, behalf of the UK NCRI AML Study Group