At the 2014 American Society of Hematology (ASH) Annual Meeting, Dr Jean-Jacques Kiladjian (Hôpital Saint-Louis & Université Paris Diderot, Paris, France) discusses a post-hoc analysis of the phase III RESPONSE trial, which compared ruxolitinib and best available therapy in patients with polycythaemia vera and splenomegaly who were intolerant of or resistant to hydroxyurea, to determine if treatment outcomes were influenced by baseline spleen volume.