LATITUDE: A phase III, double-blind, randomized trial of androgen deprivation therapy with abiraterone acetate plus prednisone or placebos in newly diagnosed high-risk metastatic hormone-naive prostate cancer.

Abstract

LBA3 Background: Pts with newly diagnosed mHNPC, particularly with high-risk characteristics, have a poor prognosis. ADT+docetaxel showed improved outcomes in mHNPC, but many pts are not candidates for docetaxel and may benefit from alternative therapy. AA+P is indicated for metastatic castration-resistant prostate cancer pts. LATITUDE evaluates clinical benefit of early intervention with AA+P added to ADT in newly diagnosed, high-risk mHNPC pts. Methods: 1199 pts with newly diagnosed (≤ 3 mos prior to randomization) mHNPC (ECOG PS 0-2) with ≥ 2 of 3 risk factors (Gleason ≥ 8, ≥ 3 bone lesions, measurable visceral metastases) were randomized 1:1 to ADT+AA (1 g QD) + P (5 mg QD) or ADT+PBOs of AA and P. Co-primary end points were overall survival (OS) and radiographic progression-free survival (rPFS). One rPFS (~565 events), 2 interim, and 1 final OS analyses (~426, ~554, and ~852 events) were planned. Results: At this first interim analysis (median follow-up of 30.4 mos; 406 deaths [48%]; 593 rPFS events), OS, rPFS, and all secondary end points significantly favored ADT+AA+P (Table). The IDMC unanimously recommended unblinding the study and crossing pts to ADT+AA+P. Grade 3/4 adverse events (ADT+AA+P vs ADT+PBOs) (%): hypertension (20.3 vs 10.0); hypokalemia (10.4 vs 1.3); increased ALT (5.5 vs 1.3) or AST (4.4 vs 1.5). Conclusions: Early use of AA+P added to ADT in pts with high-risk mHNPC yielded significantly improved OS, rPFS, and all secondary end points vs ADT+PBOs alone. ADT+AA+P had a favorable risk/benefit ratio and supports early intervention with AA+P in newly diagnosed, high-risk mHNPC. Clinical trial information: NCT01715285. [Table: see text]