I. To evaluate overall survival (OS) associated with nab-paclitaxel/gemcitabine/placebo or nab-paclitaxel/gemcitabine/AZD1775 in patients with metastatic adenocarcinoma of the pancreas. (Phase II) II. To evaluate response rate (complete response [CR] + partial response [PR]) associated with nab-paclitaxel/gemcitabine/placebo or nab-paclitaxel/gemcitabine/AZD1775 in patients with metastatic adenocarcinoma of the pancreas. (Phase II) III. To evaluate disease control rate (CR + PR + stable disease [SD]) associated with nab-paclitaxel/gemcitabine/placebo or nab-paclitaxel/gemcitabine/AZD1775 in patients with metastatic adenocarcinoma of the pancreas. (Phase II)