Abiraterone Acetate (Aa) Plus Prednisone (P) 5 Mg Qd In Metastatic Castration-Naive Prostate Cancer (Mcnpc): Detailed Safety Analyses From The Latitude Phase 3 Trial.

182Background: AA + P added to androgen deprivation therapy (ADT) improves overall survival (OS) in newly diagnosed mCNPC patients (pts). AA has been previously coadministered with P (10 mg QD). As a lower dose of P (5 mg QD) was used in LATITUDE, we conducted additional safety analyses. Methods: 1199 pts with newly diagnosed, high-risk mCNPC (≥ 2 of 3 risk factors: Gleason ≥ 8, ≥ 3 bone lesions, visceral metastases) were randomized 1:1 to AA (1 gm QD) + P (5 mg QD) + ADT or placebos (PBOs) of AA and P + ADT: median treatment duration 24 and 14 mo, respectively. Safety analyses focused on key mineralocorticoid excess (ME)-related adverse events (AEs): hypertension (HTN) and hypokalemia. Results: Increased HTN with 5 mg/d P with AA + ADT (relative risk, 1.6 [95% CI, 1.4-1.9]) was similar to prior studies using 10 mg/d P (COU-AA-301: 1.4 [0.9-2.0]; COU-AA-302: 1.6 [1.2-2.1]). Of Gr 3/4 HTN events, 87% (109/126 [AA + P + ADT]) and 83% (52/63 [PBOs + ADT]) resolved to Gr ≤ 2. There were few cerebrovascular ev...