Dimopoulos MA, Petrucci MT, Foà R, Catalano J, Kropff M, Terpos E, Zhang J, Grote L, Jacques C, Palumbo A. Impact of maintenance therapy on subsequent treatment in patients with newly diagnosed multiple myeloma: Use of ?progression-free survival 2? as a clinical trial end-point. Haematologica [Internet]. 2015;100(8):e328 - e330.