TRK-250 is a nucleic acid medicine that inhibits the progression of pulmonary fibrosis by selectively suppressing the expression of transforming growth factor-beta 1 (TGF-β1) protein, at the gene expression level. This study is a double-blind, randomized, placebo-controlled Phase I study. The primary objective of the study is to assess the safety and tolerability of single and multiple inhaled doses of TRK-250 in subjects with idiopathic pulmonary fibrosis (IPF).

Inclusion Criteria:

• Clinical, radiographic, and histologic features consistent with the diagnosis of IPF
• SpO2 ≥90% at rest by pulse oximetry while breathing ambient air.
• FVC ≥50% of predicted.
• FEV1 ≥50% of predicted.
• Ratio of FEV1 to FVC ≥0.7.
• DLCO corrected for hemoglobin 30% to 79% of predicted, inclusive.

Exclusion Criteria:

• History of acute exacerbation of IPF or respiratory tract infection within 3 months prior to Screening.
• Planned surgery during the study.
• History of malignant tumor within 5 years prior to Screening.
• History of emphysema or clinically significant respiratory diseases (other than IPF).
• Other known causes of interstitial lung disease (eg, drug toxicities, environmental exposures, connective tissue diseases).
• End-stage fibrotic disease expected to require organ transplantation within 6 months.
• Taking a systemic corticosteroid, cytotoxic therapy, vasodilator therapy for pulmonary hypertension, or unapproved treatment for IPF within 4 weeks prior to Screening. (Treatment with pirfenidone or nintedanib, though not both concurrently, is permitted, provided that the subject has been on a stable dose for at least 4 weeks prior to Screening and it is anticipated the dose will remain unchanged throughout enrollment.)