{
  "trial": {
    "name": "Phase 2 Efficacy Study",
    "design": {
      "type": "parallel",
      "n_arms": 2,
      "randomization_ratio": [0.5, 0.5]
    },
    "arms": [
      {
        "name": "Placebo",
        "regimen": {"frequency": "qd", "dose": 0.0, "duration_days": 28},
        "n": 50,
        "placebo": true
      },
      {
        "name": "Active",
        "regimen": {"frequency": "qd", "dose": 100.0, "duration_days": 28},
        "n": 50,
        "placebo": false
      }
    ],
    "duration_days": 28,
    "enrollment_rate": 5.0,
    "dropout": {"random_rate_per_day": 0.005},
    "compliance": {"mean_compliance": 0.90, "pattern": "decay"},
    "pk_sampling_times": [0, 1, 2, 4, 8, 12, 24],
    "endpoints": ["pk_exposure"],
    "seed": 42
  }
}