Androgen Receptor Pathway Inhibitor Therapy for Advanced Prostate Cancer: Secondary Analysis of a Randomized Clinical Trial

Abstract

Importance: The open-label randomized phase 2 LACOG0415 trial evaluated 3 treatment strategies for patients with advanced castration-sensitive prostate cancer (CSPC): androgen deprivation therapy (ADT) plus abiraterone acetate and prednisone (AAP), apalutamide (APA) alone, or APA plus AAP.

Objective: To investigate the association of ADT plus AAP, APA alone, or APA plus AAP with health-related quality of life (HRQOL) in patients with advanced CSPC in the LACOG0415 trial.

Design, setting, and participants: The LACOG0415 randomized clinical trial comprised 128 patients with advanced CSPC who were randomized (1:1:1) to 1 of 3 treatment arms from October 16, 2017, to April 23, 2019. Statistical analysis was conducted from March to September 2022.

Interventions: Patients were randomized (1:1:1) to 1 of 3 treatment arms: ADT plus AAP, APA alone, or APA plus AAP.

Main outcomes and measures: Health-related quality of life was evaluated using the Functional Assessment of Cancer Therapy-Prostate (FACT-P) questionnaire, including its subscales, completed at baseline and every 4 weeks until week 25. FACT-P scores range from 0 to 156, and higher scores indicate better HRQOL. Mean changes in score from baseline to week 25 were adjusted by baseline score and were calculated to evaluate whether there was a difference according to the treatment arm using a mixed-effect model for repeated measures. Time to deterioration was estimated by Kaplan-Meier curves and compared by stratified log-rank test. Analysis was performed on an intention-to-treat basis.

Results: A total of 128 patients with advanced CSPC were randomized to receive ADT plus AAP (n = 42; median age, 69.8 years [IQR, 58.9-71.6 years]), APA alone (n = 42; median age, 69.5 years [IQR, 59.8-72.6 years]), or APA plus AAP (n = 44; median age, 71.0 years [IQR, 63.0-72.3 years]). Metastatic disease was present in 95 patients (74.2%), high-risk biochemical recurrence disease in 22 (17.2%), and locally advanced disease in 11 (8.6%). There was no significant difference in baseline mean (SD) FACT-P total scores and subscales among the 3 treatment arms (FACT-P total score: ADT plus AAP arm, 118.5 [24.3]; APA alone arm, 116.1 [23.9]; AAP plus APA arm, 114.9 [18.1]; P = .69). Health-related quality of life was maintained during treatment period, and there were no statistically significant differences at 25 weeks in mean (SD) FACT-P total scores or subscales between treatment arms (FACT-P total score: ADT plus AAP arm, 122.3 [20.4]; APA alone arm, 119.5 [16.4]; AAP plus APA arm, 119.9 [20.3]). The APA alone and AAP plus APA arms were not associated with meaningful improvements in HRQOL compared with the ADT plus AAP arm, except in time to deterioration of the emotional well-being score, which was more favorable in the APA alone arm (reference arm: ADT plus AAP arm; APA alone arm: hazard ratio, 0.37 [0.15-0.85]; P = .02; ADT plus AAP arm: hazard ratio, 0.56 [0.26-1.19]; P = .13). Limitations include short follow-up period and the absence of other questionnaires to capture differences between therapies.

Conclusions and relevance: In this prespecified secondary analysis of a randomized clinical trial of ADT plus AAP, APA alone, or APA plus AAP for patients with advanced CSPC, HRQOL was not statistically different between treatments with APA alone or APA plus AAP as compared with ADT plus AAP. Larger studies with longer follow-up and more specific questionnaires are needed to further evaluate HRQOL with these treatment strategies.

Trial registration: ClinicalTrials.gov Identifier: NCT02867020.

Figure 1.. Mean Change in Functional Assessment of Cancer Therapy–General (FACT-G) Total and Functional Assessment of Cancer Therapy–Prostate (FACT-P) Scores From Baseline to Week 25

A, Mean change in FACT-G total score from baseline to week 25; theoretical score range, 0 to 108. A, Mean change in FACT-P total score from baseline to week 25; theoretical score range, 0 to 156. Error bars indicate 95% CIs. AAP indicates abiraterone acetate plus prednisone; ADT, androgen deprivation therapy; and APA, apalutamide.

Figure 2.. Mean Change in Functional Assessment of Cancer Therapy–Prostate (FACT-P) Subscales From Baseline to Week 25

A, Mean change in emotional well-being (EWB) subscale scores; theoretical score range, 0 to 24. B, Mean change in functional well-being (FWB) subscale scores; theoretical score range, 0 to 28. C, Mean change in prostate cancer subscale (PCS) scores; theoretical score range, 0 to 48. D, Mean change in social well-being (SWB) subscale scores; theoretical score range, 0 to 28. E, Mean change in physical well-being (PWB) subscale scores; theoretical score range, 0 to 28. Error bars indicate 95% CIs. AAP indicates abiraterone acetate plus prednisone; ADT, androgen deprivation therapy; and APA, apalutamide.

Figure 3.. Time to Functional Assessment of Cancer Therapy–Prostate (FACT-P) Deterioration

The FACT-P questionnaire was administered at baseline and every 4 weeks (±3 days) until week 25. AAP indicates abiraterone acetate plus prednisone; ADT, androgen deprivation therapy; and APA, apalutamide.