BACKGROUND AND OBJECTIVE: Apalutamide (APA) is a treatment for metastatic castration-sensitive prostate cancer (mCSPC). In the ARON-3 study we investigated real-world experiences with APA treatment for mCSPC. METHODS: We retrospectively assessed real-world clinical outcomes for patients with mCSPC treated with APA in the ARON-3 study. Overall survival (OS) was calculated from APA initiation to death from any cause. PSA90 was defined as a prostate-specific antigen decline of ≥90% from baseline, and PSA0.2 as achievement of a PSA level ≤0.2 ng/ml. Data for adverse events were retrospectively collected from electronic and paper charts and categorized according to Common Terminology Criteria for Adverse Events v5.0. KEY FINDINGS AND LIMITATIONS: We included 531 patients with mCSPC treated with APA. High-volume disease was reported for 214 patients (40%), and 56 (11%) had visceral metastases. Median OS was not reached. PSA90 was experienced by 461 patients (87%) and PSA0.2 by 368 (69%). Median OS was significantly longer for patients with PSA90 or PSA0.2 than for subjects without these responses (p < 0.001). The incidence of grade 3-4 fatigue was higher among elderly patients (≥80 yr) than among younger patients (19% vs 5%), but the incidence of other adverse events was comparable between the age groups. CONCLUSIONS AND CLINICAL IMPLICATIONS: APA is an effective and tolerable treatment for mCSPC in the real-world setting. PATIENT SUMMARY: The ARON-3 project collects data for patients with prostate cancer treated in multiple centers worldwide to assess outcomes in the real-world setting. We analyzed data for patients with metastatic hormone-sensitive prostate cancer receiving apalutamide. Our results show that apalutamide is a safe and effective drug in the real-world setting as well as in clinical trials.

2nd Propaedeutic Department of Internal Medicine ATTIKON University Hospital National and Kapodistrian University of Athens Athens Greece

Clinica Oncologica e Centro Regionale di Genetica Oncologica Azienda Ospedaliero Universitaria delle Marche Ancona Italy

Clinical Oncology Sociedad de Oncología y Hematología del Cesar Valledupar Colombia

Department of Health Sciences Section of Clinical Pharmacology and Oncology University of Florence Florence Italy

Department of Internal Medicine Hematology Oncology Ochsner Medical Center New Orleans LA USA

Department of Medicine and Surgery Federico 2 University Naples Italy

Department of Medicine and Surgery University of Parma Parma Italy; Medical Oncology Unit University Hospital of Parma Parma Italy

Department of Oncology and Radiotherapeutics Faculty of Medicine University Hospital in Pilsen Charles University Pilsen Czechia; Biomedical Center Faculty of Medicine in Pilsen Charles University Pilsen Czechia

Department of Precision Medicine in Medical Surgical and Critical Care Section of Medical Oncology University of Palermo Palermo Italy

Department of Urology University Hospital Bonn Bonn Germany

Division of Cancer Prevention and Genetics IRCCS European Institute of Oncology Milan Italy

Division of Medical Oncology A Policlinico Umberto 1 Rome Italy

Division of Medical Oncology Department of Internal Medicine Markey Cancer Center University of Kentucky Lexington KY USA

Hospital Israelita Albert Einstein São Paulo Brazil; Hospital Beneficência Portuguesa São Paulo Brazil

Hospital Sírio Libanês Brasília Brazil; Latin American Cooperative Oncology Group Porto Alegre Brazil

Interdisciplinary Department of Medicine Aldo Moro University of Bari Division of Medical Oncology AOU Consorziale Policlinico di Bari Bari Italy

IRCCS Istituto Tumori Giovanni Paolo 2 Bari Italy

Latin American Cooperative Oncology Group Porto Alegre Brazil; Hospital Israelita Albert Einstein São Paulo Brazil

Masaryk Memorial Cancer Institute Faculty of Medicine Masaryk University Brno Czechia

Medical Oncology 1 IRCCS Regina Elena National Cancer Institute Rome Italy

Medical Oncology 1 Unit Department of Oncology Istituto Oncologico Veneto IRCCS Padova Italy

Medical Oncology Department Tawam Hospital Al Ain United Arab Emirates

Medical Oncology IRCCS Azienda Ospedaliero Universitaria di Bologna Bologna Italy

Medical Oncology IRCCS Azienda Ospedaliero Universitaria di Bologna Bologna Italy; Department of Medical and Surgical Sciences University of Bologna Bologna Italy

Medical Oncology Santa Chiara Hospital APSS Trento Trento Italy

Medical Oncology Unit 2 Azienda Ospedaliera Universitaria Pisana Pisa Italy

Medical Oncology Unit Azienda Ospedaliera Universitaria Consorziale Policlinico di Bari Bari Italy

Medical Oncology Unit IRCCS Casa Sollievo della Sofferenza San Giovanni Rotondo Foggia Italy

Medical Oncology Unit Macerata Hospital Macerata Italy

Northern Centre for Cancer Care Freeman Hospital Newcastle upon Tyne UK

Oncology Unit ARNAS Civico Palermo Italy

Oncology Unit S Maria Delle Grazie Hospital Pozzuoli Naples Italy

Royal Marsden NHS Foundation Trust London UK

Section of Biomedicine Innovation Oncology University of Verona Verona Italy; Section of Oncology Department of Medicine University of Verona Verona University Hospital Verona Italy

Translational and Clinical Research Institute Centre for Cancer Newcastle University Newcastle upon Tyne UK

Unità Operativa di Oncologia Presidio Pugliese Ciaccio Azienda Ospedaliera Universitaria Renato Dulbecco Catanzaro Italy

UOC di Oncologia Azienda Ospedaliera di Rilievo Nazionale Cardarelli di Napoli Naples Italy

UOC Oncologia Medica Ospedale A Murri Fermo Italy

UOC Oncologia Territoriale Ausl Latina Aprilia Italy

References provided by Crossref.org