Ofatumumab monotherapy in fludarabine-refractory chronic lymphocytic leukemia: final results from a pivotal study - Osterborg, A; Jewell, RC; Padmanabhan-Iyer, S; Kipps, TJ; Mayer, J; Stilgenbauer, S; Williams, CD; Hellmann, A; Furman, RR; Robak, T; Hillman, P; Trneny, M; et al. (Haematologica, 2015)