Background: LACOG0415 is a 3-arm randomized trial evaluating ADT with abiraterone acetate plus prednisone (ADT+AAP), apalutamide alone (APA) or apalutamide with AAP (APA+AAP) for patients with locally-advanced, high-risk biochemical recurrence or metastatic castration-sensitive prostate cancer (ASCO 2020). In this trial, ADT+AAP and APA+AAP achieved the primary endpoint of percentage of patients with PSA ≤ 0.2 ng/mL at week 25. Apalutamide alone showed a high PSA decline > 50% rate, but did not achieve the pre-specified PSA threshold. Here we report patient-reported outcome data using Functional Assessment of Cancer Therapy-Prostate (FACT-P). Methods: HRQoL was measured in the overall population using the FACT-P questionnaire, comprising 5 subscales: physical wellbeing (PWB), functional wellbeing (FWB), emotional wellbeing (EWB), social/family wellbeing (SFWB), and prostate cancer subscale (PCS). Scores for each patient were measured at baseline and every four weeks until week 25. Questionnaire completion was defined as ≥ 1 question answered at an assessment time point. Analysis of HRQoL change from baseline and deterioration included only patients with baseline and ≥ 1 postbaseline score. Differences greater than 10-points in FACT-P total score and differences greater than 3-points in PWB, FWB, EWB, SFWB, and PCS scores were considered clinically significant. The time-to-event endpoint was estimated by Kaplan-Meier method and compared by stratified log-rank test. Results: 128 patients were included in LACOG0415 trial and 122 of them completed the HRQoL assessments (ranging from 95.3% at baseline to 79.7% at week 25). FACT-P and all subscales scores were similar for all three arms at baseline. There were no meaningful differences in FACT-P scores at baseline and at week 25 between the 3 arms. The subscales scores also showed no statistically differences at baseline and at week 25. Time to FACT-P deterioration did not show any statistically difference between three arms (P=0.3371). Conclusions: ADT free alternatives with APA alone or APA+AAP did not show meaningful differences in HRQoL in patients with advanced castration-sensitive prostate cancer compared to ADT+AAP. The short follow-up period limited the ability to explore differences in HRQoL after 25 weeks. Larger studies with longer follow-up are needed to further evaluate HRQoL with ADT-free strategies. Clinical trial information: NCT02867020