Real-world treatment landscape in advanced metastatic castration resistant prostate cancer.

Abstract

e17032 Background: Despite a rapidly evolving treatment landscape in advanced prostate cancer (aPC) marked by recent emergence of therapies such as radioconjugates and PARP inhibitors, outcomes remain poor for many patients. Future care improvements will require innovative treatments and simplifying treatment planning. The goal of this study is to understand how the evolving treatment landscape has impacted care and outcomes in patients with aPC using real world (rw) data. This study evaluates outcomes of mCRPC patients who have advanced to a 3rd line of therapy (L3) with prior exposure to both an androgen receptor signaling inhibitor (ARSI) therapy and a taxane or platinum-based chemotherapy, in any aPC disease setting. Methods: mCRPC patients in the Flatiron Database who progressed to L3 with pre-L3 exposure to both an ARSI (abiraterone, enzalutamide, apalutamide, and darolutamide) and chemotherapy (cabazitaxel and docetaxel) were eligible for inclusion. Patients whose mCRPC diagnosis occurred between Dec 2010 and Nov 2023 were included. As the objective was to study the aPC treatment landscape, patients with prior exposure to therapies approved in the mCRPC disease setting such as radioconjugates, PARP inhibitors, radiation, investigational and palliative drugs were excluded. Outcomes were reported as median real-world overall survival (rwOS) indexed to start of L3 treatment, and median rw time to next treatment (rwTTNT) from the start of L3 to the beginning of L4 treatment. Results: 660 patients met all inclusion criteria and had at least one year of treatment history in the aPC disease setting. Median follow up time (indexed to L3 start) for all patients was 7.55 months. Median rwOS for all patients was 10.8 months (95% CI 9.9 - 12.2), while median rwTTNT was 5 months (95% CI 4.6 - 5.4). The most common L3 therapy class was chemotherapy, followed by ARSIs (Table). To aid in treatment planning strategies, drug sequence patterns were also analyzed. Frontline ARSIs were followed by second line chemotherapy for most of the patients (n = 349; 53%). Conclusions: Relatively short survival times and short durations on L3 therapies for aPC demonstrate a high unmet need, with therapeutic options dominated by ARSIs and chemotherapy. Recently approved radioconjugate therapies, like Pluvicto â, have reported median OS 15.3 months (Fallah, 2023) in prostate-specific membrane antigen (PSMA)-positive patients, which is greater than the 10.8 months observed in general mCRPC population analyzed in this study. These findings underscore the need to develop effective therapies and treatment strategies that are tailored for advanced prostate cancer. [Table: see text]