After a median follow-up of 31 months ( IQR 19-42 ) , median time to progression was significantly longer in the salvage ASCT than in the cyclophosphamide group ( 19 months [ 95 % CI 16-25 ] vs 11 months [ 9-12 ] ; hazard ratio 036 [ 95 % CI 025-053 ] ; p < 00001 ) .