Authors: Andrew J. Armstrong, Taro Iguchi, Arun Azad, Arnauld Villers, Boris Alekseev, Daniel P. Petrylak, Russell Zelig Szmulewitz, Antonio Alcaraz, Neal D. Shore, Jeffrey Holzbeierlein, Francisco Gomez-Veiga, Brad Rosbrook, Fabian Zohren, Gabriel P. Haas, Georgia Gourgioti, Nader N. El-Chaar, Arnulf Stenzl
Published: 2021-06-02
DOI: 10.1200/jco.2021.39.15_suppl.5071
Source: Full article
5071 Background: In ARCHES (NCT02677896), ENZA + ADT reduced the risk of radiographic progression and improved secondary clinical outcomes in patients with metastatic hormone-sensitive prostate cancer (mHSPC) with variable patterns of disease spread over placebo (PBO) + ADT. This post hoc analysis aimed to evaluate the efficacy of ENZA + ADT in patients with bone oligometastatic mHSPC compared to polymetastatic mHSPC in ARCHES. Methods: Patients with mHSPC (n = 1150) were randomized 1:1 to ENZA (160 mg/day) + ADT or PBO + ADT, stratified by disease volume and prior docetaxel chemotherapy. This post hoc analysis included patients with bone metastases only, categorized as oligometastatic (1–≤5 metastases) or as polymetastatic (≥6 metastases) based on central review at screening. Efficacy outcomes were compared across treatment arms. Results: Of the ARCHES population with bone metastases (n = 512), the largest subgroup included patients with ≤5 metastases (ENZA + ADT, n = 160; PBO + ADT, n = 136). Baseline characteristics were generally comparable between treatment arms and across subgroups. When compared to PBO + ADT, ENZA + ADT improved rPFS and secondary endpoints in patients with ≤5 metastases (Table). Similar results were observed across other oligometastatic subgroups (1–≤4) as well as in polymetastatic disease (≥6). The safety profile of ENZA + ADT versus PBO + ADT was similar across subgroups and consistent with previous findings. Conclusions: This post hoc analysis demonstrates that ENZA + ADT provides clinical benefit across bone oligometastatic as well as polymetastatic mHSPC, supporting the utility of ENZA irrespective of metastatic burden in the ARCHES study. Clinical trial information: NCT02677896. [Table: see text]