The Mito8 Phase 3 International Multicenter Randomized Study Testing The Effect On Survival Of Prolonging Platinum-Free Interval (Pfi) In Patients With Ovarian Cancer (Oc) Recurring Between 6 And 12 Months After Previous Platinum Based Chemotherapy. A Collaboration Of Mito, Mango, Ago Study Group, Bgog, Engot, And Gcig