Objective: To investigate whether the extent of peritoneal disease may predict the survival benefit from IP/IV therapy. Design: A TFS analysis. Setting: Censored on August 27, 2020, the extended follow-up of AICE (Additional Intraperitoneal Cisplatin and Etoposide in ovarian cancer) trial. Population: Patients were categorized into the high tumor burden (HTB) and low tumor burden (LTB) subgroups. Methods: Overall survival (OS) was partitioned into time on protocol treatment exposure (T), time to subsequent treatment initiation or death (TFS), and time after first subsequent therapy or death (REL). TFS analyses and quality-adjusted OS were calculated by multiplying mean time in each health state by its assigned utility (Quality-adjusted OS =ut *T+TFS+urel *REL). Main Outcome Measures: The area under each Kaplan-Meier curve was estimated by the 96-month restricted mean time, with the threshold utility analyses illustrating the quality-adjusted OS comparisons. Results: In the HTB subgroup, restricted mean TFS was 33.9 months and 18.7 months in the IP/IV and IV groups, respectively (difference, 15.2 months; 95%CI, 4.6 to 25.7; P = .005), with a significant quality-adjusted OS gain (ranging from 13.2 to 16.0 months). In the LTB subgroup, there was no survival benefit from IP/IV therapy in either TFS (difference, 7.1 months; 95%CI, -5.5 to 19.8; P = .268) or quality-adjusted OS (ranging from 1.4 to 6.3 months). Conclusions: IP/IV therapy provided significantly longer TFS and quality-adjusted OS across all values of utility weights than standard IV therapy in the HTB subgroup, while patients did not benefit from it in the LTB subgroup.