Cough Reduction in IPF With Nalbuphine ER

A Randomized, Double-Blind, Placebo-Controlled, Parallel, 4-Arm Dose Ranging Study of the Safety and Efficacy of Nalbuphine Extended-Release Tablets (NAL ER) for the Treatment of Cough in Idiopathic Pulmonary Fibrosis (IPF)

The main purpose of the study is to evaluate the effect of NAL ER on 24-hour cough frequency using objective digital cough monitoring and to assess safety and tolerability of NAL ER.

Inclusion Criteria:

• Diagnosis of IPF as determined by the Principal Investigator based on ATS/ERS/JRS/ALAT guidelines.
• Cough Severity Score ≥ 4 on CS-NRS (Cough Severity Numerical Rating Scale) during the Screening period and Baseline.
• History of chronic cough for at least 8 weeks before screening.
• SpO2 ≥ 92%, taken after at least 5 minutes in a sitting position, undisturbed and non-stimulated (Saturation of Hemoglobin with Oxygen as Measured by Pulse Oximetry).
• FVC ≥ 40% predicted of normal - Forced Vital Capacity, as determined by spirometry adhering to ATS/ERS guidelines.
• DLCO ≥ 25% predicted of normal - Diffusing capacity of the lung for carbon monoxide corrected for hemoglobin, assessed within the last 12 weeks, or at the time of screening.

Exclusion Criteria:

• Currently on continuous oxygen therapy for longer than 16 hours at any level or delivered by any modality. Intermittent oxygen use of any duration over any given 24-hour period is allowed.
• Inadequate swallow reflex as assessed by the ability to sip 3 fluid oz (or 89 mL) of water without coughing or choking.
• Upper or lower respiratory tract infection in the last 8 weeks prior to the baseline visit.
• Clinical history of aspiration pneumonitis.
• Diagnosis of sleep apnea.
• Abnormal kidney or liver functions based on Screening lab results.
• Known hypersensitivity to nalbuphine or to NAL ER excipients
• History of major psychiatric disorder.
• History of substance abuse.
• Significant medical condition or other factors that may interfere with the participant's ability to successfully complete the study.
• Pregnant or lactating female participant.
• Known intolerance (gastrointestinal, central nervous system symptoms), hypersensitivity, drug allergy following the use of an opioid drug.
• Use of opiates is prohibited within 14 days prior to the baseline visit.
• Use of benzodiazepines are prohibited within 14 days prior to the baseline visit and for the duration of the study.
• Monoamine oxidase inhibitors (MAOIs) including methylene blue (methylthioninium chloride) and the antibiotic linezolid are prohibited within 14 days prior to the baseline visit and for the duration of the study.
• Use of oral corticosteroid cough treatment is prohibited within 4 weeks prior to the baseline visit and for the duration of the study.
• Exposure to any investigational medication, including placebo, is prohibited within 4 weeks prior to the baseline visit and for the duration of the study.
• Medications prescribed as cough suppressants are prohibited unless on a stable dose 14-days prior to the baseline visit and are expected to remain on that dose for the duration of the study.
• Use of medications that affect serotonergic neurotransmission and that when used concomitantly with opioids can increase the risk of serotonin syndrome are prohibited unless on a stable dose 14-days prior to the baseline visit and are expected to remain on that dose for the duration of the study.
• Anti-fibrotic medications are prohibited unless on a stable dose for 8 weeks prior to the baseline visit and are expected to remain on that dose for the duration of the study.
• Strong inhibitors/inducers of the P450 Isozymes are prohibited unless on a stable dose for 14-days prior to baseline visit and are expected to remain on that dose for the duration of the study.
• Use of a medication having a "known risk" of Torsade de Pointes (categorized as "KR" on the Credible Meds® website.) 4 weeks prior to Baseline.
• Use of unstable doses of medications associated with a potential risk of QT prolongation but not clearly associated with Torsade de Pointes within 4 weeks of screening.

Other protocol defined inclusion/exclusion criteria may apply.