Clinical Study of ART-123 for the Treatment of Acute Exacerbation of Idiopathic Pulmonary Fibrosis

Main Inclusion Criteria: * Patients diagnosed with IPF who meet all criteria from (1) through (4) during the course of IPF * (1)Unexplained development or worsening of dyspnea within 1 month during the course of IPF * (2)Finding of new, bilateral ground glass opacities and/or consolidation on HRCT * (3)No apparent Pulmonary infections, pneumothorax, malignant tumors, pulmonary embolism, or left heart failure * (4)A decrease\* in PaO2 of ≥10 mmHg or SpO2 of ≥4% under the same conditions compared with the level at the previous measurements * (\*) In cases where no PaO2 or SpO2 test values under the same conditions are available, a patient with a P/F ratio ≤300 in the current episode of acute exacerbation is considered to have met criterion (4) * Aged 40 years or older and no older than 85 years at the time of informed consent with either sex Main Exclusion Criteria: * Have intracranial hemorrhage, pulmonary hemorrhage, gastrointestinal bleeding (continued hematemesis, bloody discharge, gastrointestinal ulcer-induced hemorrhage) * Have a history of cerebrovascular disorder (e.g., cerebral hemorrhage or cerebral infarction) within 52 weeks (364 days) before informed consent * Patients for whom the completion of hemostatic treatment has not been confirmed after undergoing surgery of the central nervous system or after trauma * Have a high risk for fatal or life-threatening hemorrhage * Patients with malignant tumors * Have acute exacerbation attributable to drug induced pulmonary disorder, after surgery for malignant tumors, chemotherapy, or radiation therapy * Have acute exacerbation due to a thoracic surgical procedure (including thoracoscopic lung biopsy) * Have a history of acute exacerbation of IPF * Receiving mechanical ventilation through intratracheal intubation * Patients who are pregnant or nursing, or who may be pregnant * Patients with a platelet count less than 100,000/uL at the time of enrollment * Patients with severe renal (serum Cr: ≥4 mg/dL) or hepatic (AST/ALT: ≥500 IU/L or T-Bil: ≥10 mg/dL) dysfunction * Have been administered a commercially available thrombomodulin alfa (recombinant )(Recomodulin® for Intravenous Injection 12800) within 30 days before the start of investigational product administration * Have a history of hypersensitivity for investigational product