Prostate-specific Antigen at 3 Months as a Predictor of Radiologic Progression-free Survival in Metastatic Hormone-sensitive Prostate Cancer Treated with Apalutamide: Analysis of 633 Patients in a Real-world Database

• Published in: European urology open science (Online) Vol. 70; pp. 58 - 63
• Main Authors: Hassi Roman, Mario, Mate, Kinga, De Pablos-Rodriguez, Pedro, Horcajada, Álvaro Zamora, Cascales, Ana Guijarro, Bonet, Ángeles Sanchís, Vilaseca, Antoni, Vázquez-Martul Pazos, Darío, Espinós, Estefanía Linares, Rodríguez, Jesús Muñoz, de la Morena Gallego, José Manuel, Alemán, José Ramón, Rivas, Juan Gómez, Formisano, Luigi, Juan Fita, Maria J., Planells, Marc Costa, Esteban, Mario Domínguez, Márquez, Meritxell Pérez, Sanz, Miguel García, Expósito, Nagore García, Picola, Natalia, Vives, Pol Servian, Sutil, Raquel Sopeña, Climent Durán, Miguel A., Backhaus, Miguel Ramírez
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.12.2024; Elsevier
• Subjects: Apalutamide; Metastatic hormone-sensitive prostate cancer; Prostate Cancer; Prostate-specific antigen; Response; Ultrasensitive assay; Urology; Apalutamide; Response; Metastatic hormone-sensitive prostate cancer; Ultrasensitive assay; Prostate-specific antigen; Prostate cancer
• ISSN: 2666-1683; 2666-1691; 2666-1683
• DOI: 10.1016/j.euros.2024.10.001

The prostate-specific antigen response to apalutamide at 3 mo predicts radiologic progression-free survival for patients with metastatic hormone-sensitive prostate cancer. Those with a complete response have a low risk of progression at 2 yr, while nearly half of patients with an incomplete response will experience progression. Identification of patients who benefit from specific therapies is crucial for effective treatment decisions and clinical management. The depth of the prostate-specific antigen (PSA) decline after androgen receptor pathway inhibitor (ARPI) treatment combined with androgen deprivation therapy for patients with metastatic hormone-sensitive prostate cancer (mHSPC) may affect prognosis. The primary objective in our study was the correlation between the PSA response at 3 mo and radiologic progression-free survival (rPFS) at 24 mo. Three groups were defined according to the PSA decline: complete response (PSA ≤0.02 ng/ml), partial response (PSA >0.02 and ≤0.2 ng/ml), and incomplete response (PSA >0.2 ng/ml). Secondary objectives were correlation between the PSA response at 3 mo and overall survival, and the development of a model predicting complete PSA response. We conducted a retrospective multicenter study of patients with mHSPC treated with apalutamide from May 2018 to September 2023 registered in the Real-World Evidence APA registry across 20 centers. We included 633 patients with mHSPC. The median age at diagnosis was 68 yr (interquartile range [IQR] 63–75) and median PSA was 16 ng/ml (IQR 7.5–64). Some 63% of the short had low-volume disease, 51% had de novo disease, 48% had recurrent disease. At 3 mo, 27% had a complete response, 42% a partial response, and 31% an incomplete response, with corresponding rRFS rates at 24 mo of 92%, 86%, and 63%. According to the predictive model, a complete PSA response at 3 mo was associated with the use of next-generation imaging and PSA <50 ng/ml at diagnosis. Study limitations include heterogeneity among the groups and variations in data quality and assessment methods. Patients with a complete PSA response after 3 mo of apalutamide treatment face a very low risk of progression within 2 yr. Conversely, nearly 50% of patients with an incomplete PSA response will experience disease progression. For patients with metastatic prostate cancer that is still responsive to hormone therapy, a complete response after treatment with a drug called apalutamide is associated with a very low risk of progression within 2 years. However, nearly half of patients with an incomplete response to apalutamide will experience progression of their cancer.