A Real World Observational Study Characterizing Patients With Advanced Prostate Cancer Treated With or Without Androgen Receptor-Pathway-Inhibitor Therapies in Alberta, Canada

Data are needed to improve the current understanding of clinical management and characteristics of patients with advanced prostate cancer (PC) treated with androgen receptor pathway inhibition (ARPI) therapy. This retrospective cohort study using real-world, population-level data from Alberta, Canada included all individuals diagnosed in 2017-2020 with de novo metastatic castration-sensitive PC (mCSPC) or nonmetastatic castration-resistant PC (nmCRPC) who initiated androgen deprivation therapy (ADT). For mCSPC, patients were classified as ARPI-exposed if they received an ARPI within 180 days of initiating ADT, while patients with nmCRPC were classified as ARPI-exposed if they received an ARPI within 2 years of diagnosis. This study included 976 patients with mCSPC and 233 with nmCRPC of which 33.5% and 25.3% received an ARPI, respectively. The proportion of patients with mCSPC treated with an ARPI increased considerably for patients diagnosed in 2020 compared to 2017 (56.2% vs. 6.0%). In contrast, the use of ARPI to treat nmCRPC only increased marginally from 2017 to 2019/2020 (19.7% vs. 28.9%). Patients with mHSPC who were ARPI-exposed had longer median survival than patients who were ARPI-naive (38.47 (95% CI = 32.84-NA) vs. 34.19 (95% CI = 33.33-38.83; P = .03)), with a higher proportion of patients surviving to 2-years. For nmCRPC, survival was similar between ARPI-exposed and ARPI-naive. In multivariable analyses, receiving ARPI for mCSPC was associated with younger patient age, more recent diagnoses, fewer comorbidities, a higher number of metastatic sites, referral to a medical oncologist as well as receiving surgery and radiation before ADT. Receiving ARPI for nmCRPC was associated with referral to a medical oncologist, younger age, and more recent diagnoses. Outcome analyses in this population suggest a continued unmet clinical need and complex clinical management pathways. Given that treatment pathways have evolved considerably, continued follow-up to understand the impact of these advancements on patient outcomes are warranted. Treatment intensification is now standard of care for metastatic castration sensitive prostate cancer (mCSPC) and nonmetastatic castration resistant prostate cancer (nmCRPC). Among 976 patients with mCSPC and 233 with nmCRPC diagnosed in Alberta, Canada in 2017-2020, treatment intensification with ARPIs increased considerably for patients with mCSPC, but uptake is still low. Younger age, fewer comorbidities, higher metast