Real-World Evidence of Combination Therapy Use in Metastatic Hormone-Sensitive Prostate Cancer in the United States From 2017 to 2023.

Purpose: Treatment of metastatic hormone-sensitive prostate cancer (mHSPC) has evolved with robust clinical trial evidence on the benefits of combining androgen-deprivation therapy (ADT) with androgen receptor pathway inhibitors (ARPIs; abiraterone, apalutamide, darolutamide, and enzalutamide) and/or docetaxel (DOC). To understand current treatment approaches in clinical practice, we examined combined therapy for mHSPC in US real-world practice.

Methods: This retrospective study used administrative claims in the Komodo Research Dataset (January 2016-September 2023). Individuals with mHSPC were identified on the basis of their earliest claim for metastasis on/after prostate cancer diagnosis date without evidence of castration resistance. Index date was the earliest ADT claim after mHSPC. Combination therapy included the addition of ARPI, DOC, or both to ADT within 4 months of index date. Multinomial regression was used to examine factors associated with combination therapy.

Results: Study population consisted of 10,717 individuals, with a median age of 65 years and a majority of de novo mHSPC cases at diagnosis (62%). Overall, 28% received combination therapy with ARPI (18% abiraterone; 10% apalutamide, darolutamide, or enzalutamide), 9% with DOC, and 2.5% with ARPI plus DOC. From 2017 to 2023, combined hormonal therapy with ARPI increased from 13% to 47% and with ARPI plus DOC from 0.8% to 15%, whereas use of ADT plus DOC declined from 12% to 3% and ADT alone from 74% to 36%. Key factors associated with combination therapy were younger age, fewer chronic comorbidities, de novo mHSPC, and bone metastases.

Conclusion: Although one third of men received ADT alone in 2023, the use of combination hormonal therapy with ARPI and/or DOC increased between 2017 and 2023, highlighting uptake of guideline-recommended treatment, driven by available clinical evidence, disease burden, and tolerability.