Inclusion Criteria:

• - Diagnosis of idiopathic pulmonary fibrosis (IPF) according to the 2018 American Thoracic Society (ATS) guidelines, confirmed by high-resolution computed tomography (HRCT) chest scan taken within < 2 years.

• - Age ≥ 18 years.

• - Cough attributed to IPF unresponsive to standard anti-tussive treatment and present for > 8 weeks.

• - Arithmetic mean of ≥ 10 coughs/hour during waking hours.

• - Ability to read, comprehend, and complete the informed consent form (ICF) and all questionnaires in the study without help.

• - Cough severity score of ≥ 40 mm on a 0-to-100 mm Visual Analogue Scale (VAS) - Life expectancy > 6 months.

• - Stable medical condition: stable treatment for > 12 weeks and absence of acute exacerbations for > 4 weeks.

• - Antifibrotics pirfenidone and nintedanib are allowed if the patient has been on a stable dose for ≥ 12 weeks and remains on a stable dose throughout the study.

• - Forced vital capacity (FVC) ≥ 40% predicted.

• - Ratio between forced expiratory volume in one second and forced vital capacity (FEV1 / FVC) ≥ 65% - Women of childbearing potential must agree to use a highly effective method of contraception.

• - Male partner must agree to use a condom during the study, unless they had a vasectomy > 6 months prior to first study drug administration.

Exclusion Criteria:

• - Likely need for lung transplantation in next 12 months.

• - Permanent long-term oxygen therapy.

• - Use of high-dose corticosteroids or cytotoxic medications.

• - History of unstable or deteriorating cardiac or pulmonary disease in the preceding 6 months.

• - Current smoking, vaping, or tobacco chewing.

• - Treatment with an angiotensin-converting enzyme (ACE) inhibitor or sitagliptin started in the last 12 weeks.

• - Suspected acute infection, including COVID-19 or influenza or any upper respiratory tract infection.

• - History of malignancy within the last 2 years.

• - History of drug/alcohol dependency/abuse within the last 2 years.

• - Recent history of stroke or transient ischemic attack.

• - Blood pressure > 160/90 mmHg.

• - Pregnant/lactating women.

• - Exposure to an investigational drug or biologic within the last 2 months.

• - Blood donation within the last 56 days or plasma donation within the last 7 days.

- Body Mass Index < 18 kg/m2 or ≥ 40 kg/m2

This double-blind, cross-over, placebo-controlled clinical trial will randomize patients with stable idiopathic pulmonary fibrosis (IPF) and cough related to IPF (IPF-cough) in a 1:1 fashion to one of two treatment sequences: active treatment followed by placebo, or placebo followed by active treatment. Each 14-day active/placebo treatment phase is preceded by a wash-out period. The treatment sequences are followed by an observational 7-day follow-up period without medication. All subjects in the trial receive standard-of-care antifibrotic treatment for IPF. Treatment assignment is blinded to patients, investigators, site personnel, data analysts and Sponsor. The active treatment is ME-015 (Suplatast Tosilate) 200 mg t.i.d. (three times per day) administered as oral capsules. The placebo treatment consists of identical capsules without the active component. The primary efficacy endpoint is the effect on wake time cough frequency measured objectively with the VitaloJak device over a 24-hour period. VitaloJak recordings are analysed using a blinded, independent, central review process. The study is conducted as a single-country, multi-site clinical trial in India with Melius Pharma AB as the Sponsor.

Arms

Experimental: ME-015 (Suplatast Tosilate)

ME-015 (Suplatast Tosilate) 2 x 100 mg capsule t.i.d. (three times per day), for 2 weeks

Placebo Comparator: Placebo

Identical placebo capsules 2 x t.i.d. (three times per day), for 2 weeks

Interventions

Drug: - ME-015 (Suplatast Tosilate)

Oral capsule form, 200 mg t.i.d. (total 600 mg per 24 hours)

Other: - Identical placebo

Without active component