Real-world trends in the evolving use of first-line therapy in metastatic castration-sensitive prostate cancer patients (mCSPC) in the United States.

e23384 Background: Management strategies for frontline therapy of mCSPC is rapidly evolving. Current standards of care include androgen deprivation therapy (ADT) combined with androgen receptor pathway inhibitors (ARPIs), as well as triplet regimens incorporating ADT + docetaxel chemotherapy, and ARPIs and recently with added poly-ADP ribose polymerase inhibitors (PARPi) in selected patients. These approaches have largely superseded ADT monotherapy. However, treatment intensification continues to be reportedly underutilized. This study aims to characterize real-world patterns and changes over time of frontline therapy with ADT doublet, triplet therapy or ADT monotherapy in men with mCSPC and assess survival differences. Methods: A retrospective cohort of men with prostate cancer was derived from the ConcertAI Patient360 Prostate Cancer Dataset. Patient characteristics and demographics were abstracted and treatment using ADT and combination therapies were defined by completing at least 6 months of first-line therapy. Results: Of the 17,736 patients (pts) included in the database from years 1988 to 2024, 5972 patients had stage IV prostate cancer with mCSPC, of whom treatment details were extracted from 2015 to 2024 in 2973 pts. Mean age at time of first treatment was 65.0 years (range 40 – 79). Caucasians made up 2132 pts (72%), Blacks 501 (17%), Asians 47 (2%), Others 293 (10%). The majority of patients were treated in Community centers: 2614 (88%) and Academic centers 359 (12%). Geographically, treatment occurred mainly in the South 1135 (38%), followed by the Midwest 688 (23%), the Northeast 559 (19%) and the West 478 (16%). ADT doublet was the most common first-line therapy utilized in 1615 (54%), with Other (519) and ADT Triplet (506) at 17% each. ADT monotherapy comprised 229 (8%) of pts. ADT combination therapy use has trended upward from 42% to 57% (ADT doublet) and 15% to 28% (ADT triplet) during the study period. Additionally, ADT monotherapy has trended downward from 10% to 5% during the same time. The utilization of primary definitive radiation in mCSPC pts occurred in 526 (18%) while surgery in 278 (9%), although lesser Black pts underwent radiation in 60 (12%) and surgery in 28 (6%), respectively. Conclusions: ADT doublet therapy with ARPI is the most commonly utilized frontline therapy for mCSPC in the US with corresponding decline in ADT monotherapy use over time, suggesting emergence of guideline-concordant care. While triplet therapy use is rising, it remains lower than ADT doublet use. Further investigation is needed to discern trends in survival in a real-world setting.