Main Session
Sep
30
PQA 07 - Genitourinary Cancer, Patient Safety, Nursing/Supportive Care
3300 - Management of Metastatic Castration-Resistant Prostate Cancer (mCRPC) at the Veterans Affairs Healthcare System (VAHCS): A Real-World Assessment of Modern Patterns of Care, Oncologic Outcomes, and Adverse Events (AEs)
Presenter(s)
Anthony Nguyen, MD, PhD - Cedars-Sinai Medical Center, Los Angeles, CA
A. T. Nguyen1, R. Zheng2,3, J. Nguyen4, J. Patel4, X. Wang4, B. Kang4, A. De Hoedt5, J. A. Parrish5, S. Cummings5, and S. J. Freedland5,6; 1Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, CA, 2Department of Urology, Cedars-Sinai Medical Center, Los Angeles, CA, 3School of Medicine, Tsinghua Medicine, Tsinghua University, Beijing, China, 4Novartis Pharmaceuticals Corporation, East Hanover, NJ, 5Department of Surgery, Section of Urology, Durham VA Health Care System, Durham, NC, 6Center for Integrated Research in Cancer and Lifestyle, Cedars-Sinai Cancer Institute, Los Angeles, CA
Purpose/Objective(s):
Radioligand therapy (RLT) is a new standard-of-care treatment option for patients (pts) with mCRPC in the post-androgen receptor pathway inhibitor (ARPI) and taxane-based chemotherapy setting; however, the optimal treatment sequence of systemic therapy prior to RLT is unknown. Herein, we characterized the modern treatment patterns of care, oncologic outcomes, and AEs in pts with mCRPC who received =1 ARPI or taxane at the VAHCS.Materials/Methods:
This retrospective, observational study used VAHCS claims data from pts diagnosed with mCRPC between January 2018 and February 2024. We included pts with mCRPC who received either ARPI (abiraterone, enzalutamide, darolutamide, or apalutamide; [ARPI cohort]) or taxane (docetaxel or cabazitaxel; [taxane cohort]) pre- or post-mCRPC. Date of receipt of first ARPI or taxane was the index date. Pts could have received androgen deprivation or radiation therapy >6 months prior to the index date. Kaplan–Meier (KM) analysis was used to estimate overall survival (OS) and multivariable Cox regression analyses were performed to adjust for patient- and disease-related covariates.Results:
In total, 2982 pts receiving =1 ARPI or taxane and diagnosed with mCRPC (before or after 1L treatment) were included. Most pts initially received an ARPI (n=2828, 95%) with only 154 (5%) receiving a taxane. Pts in the ARPI cohort were significantly older (median 74 vs 68 years; p<0.001). Most patients initiated taxane (87%, n=134) and ARPI (54%, n=1535) prior to mCRPC diagnosis. Median OS following ARPI initiation was 34.0 months (95% confidence interval [CI]: 32.0–36.0) and 34.0 months (95% CI: 28.0–46.0) following taxane initiation (p=0.498). While the risk was trending lower, the type of 1L therapy was not significantly associated with univariate (log-rank, p=0.498) or multivariable OS (Cox model hazard ratio: 0.85; 95% CI: 0.67–1.06; p=0.152) when accounting for race, ethnicity, geographic region, and time from PC diagnosis to 1L therapy. Only 14% of all pts received third-line (3L) systemic therapy. The proportion of pts with =3 AEs were significantly higher in the taxane cohort compared with ARPI cohort (61% vs 34%, respectively; p<0.001). The most common AEs for all pts were infection (30%), fatigue (26%), bone pain (25%), arthralgia (24%), and anemia (23%).Conclusion:
Although the choice of ARPI and taxane as 1L did not appear to influence OS in pts with mCRPC, taxane chemotherapy was associated with significantly higher AEs compared with ARPI. In the VA equal-access healthcare system, most pts received ARPI or taxane prior to mCRPC diagnosis in this modern cohort; however, survival remained suboptimal with few pts getting 3L, highlighting the potential unmet need to introduce additional therapies earlier.