Enzalutamide for Primary Immune Prostate Cancer in Routine Clinical Practice: Results from a Rare Metastasis Study in Japan

Abstract

Introduction: The effectiveness and safety of romiplostim were evaluated by immune thrombocytopenia (ITP) phase (newly diagnosed/persistent/ chronic) at romiplostim initiation.

Methods: This is a post hoc analysis of a prospective, Japanese, multicentre, observational study in adults with ITP who received ≥1 dose of romiplostim. Follow-up data were collected for ≤2 years. Outcomes included overall platelet response (≥1 platelet count ≥50 × 109/L at 2–24 weeks after romiplostim initiation) or durable platelet response (≥75% of measurements ≥50 × 109/L at 14–24 weeks) and adverse drug reactions (ADRs), evaluated by ITP phase.

Results: Data from 96 patients were analyzed (newly diagnosed, n = 18; persistent, n = 25; chronic, n = 53). During the 2- to 24-week follow-up, overall platelet response was achieved in 100% (95% confidence interval: 81.5–100), 100% (86.3–100), and 96.2% (87.0–99.5) of patients with newly diagnosed, persistent, or chronic ITP, respectively, and platelet responses were durable in 88.2% (63.6–98.5), 65.0% (40.8–84.6), and 69.4% (54.6–81.7) of patients. During the 2-year follow-up, ADRs occurred in 24.0–35.8% of patients across phases. Two patients with chronic ITP experienced bone marrow ADRs; no thrombotic ADRs occurred.

Conclusion: Romiplostim was effective and well tolerated in patients with newly diagnosed, persistent, or chronic ITP in routine clinical practice.