This trial is a randomized, double-blind, placebo-controlled study evaluating the safety and preliminary efficacy of inhaled Nintedanib Dry Powder Inhalation (DPI) in adults with idiopathic pulmonary fibrosis (IPF). Participants are randomized to receive either 2 mg QID, 4 mg BID, or matching placebo for 12 weeks, followed by a 24-week open-label extension in which all participants receive active treatment. The primary focus is on safety-particularly bronchospasm events, lung function changes (FEV1, FEV1/FVC), and adverse event rates and assessing the effectiveness of nintedanib DPI in treating IPF.

Inclusion Criteria:

• 40-80 years old when signing consent and entering screening.
• Diagnosed with IPF based on current ATS/ERS/JRS/ALAT guidelines.
• Either new to treatment or on a stable dose of pirfenidone and/or nerandomilast for at least 3 months before screening.
• Weighs more than 40 kg (88 lb) at screening.
• Women who can become pregnant:
• Must have a negative pregnancy test at screening.
• Must use an approved birth control method from screening until at least 1 month after the last study dose.
• Men who can father a child and are sexually active with women who can become pregnant:
• Must use an approved birth control method during treatment and for at least 3 months after the last study dose.
• Must not donate sperm during treatment and for at least 3 months after the last study dose.
• Willing to follow all study rules and restrictions.
• Willing and able to attend study visits and complete study procedures.
• Able to perform spirometry (lung function testing) as required by the study.

Exclusion Criteria:

• Has a lung disease caused by something other than IPF.
• Has a connective tissue or autoimmune disease (such as lupus, scleroderma, or rheumatoid arthritis).
• Has another condition that significantly affects breathing.
• Has serious heart or blood vessel disease.
• Has a recent or current infection.
• Was recently hospitalized for COVID-19, an IPF flare-up, or a lung infection.
• Has a history of asthma (except childhood asthma that has resolved).
• Has another medical condition or abnormal test result that may affect study participation or safety.
• Cannot perform high-quality spirometry testing.
• Has obstructive lung disease.
• Has abnormal liver function tests.
• Has moderate to severe liver disease.
• Has severe kidney disease.
• Has recently used high-dose steroids or other immune-suppressing medications.
• Has active cancer or recent cancer treatment.
• Is on, or expected to be added to, a transplant list.
• Had major surgery recently or has planned procedures that could interfere with the study.
• Has had a severe reaction to nintedanib or cannot take nintedanib safely.
• Has recently used certain medications that may interact with the study drug.
• Is currently using, or plans to use, prohibited medications during the study.
• Has recently participated in another clinical trial.
• Has current alcohol or drug abuse issues.
• Donated a significant amount of blood recently.
• Received a live vaccine recently.
• Currently smokes, recently smoked, or quit smoking less than 1 year ago.
• Requires more than 6 L/min of oxygen while at rest.