This is a trial designed to evaluate the combination of nerandomilast with mycophenolate across a wide variety of pulmonary fibrosis subtypes, with the aim of providing clinicians with assurance that this is an appropriate therapeutic combination.

Inclusion Criteria:

• Any underlying pulmonary fibrosis diagnosis (excluding IPF) with ≥ 10% fibrosis on chest HRCT (performed within 1 year of screening) by volume assessment as determined by the treating physician
• Anticipated benefit from nerandomilast therapy as determined by the treating physician (note that previous observed progression as defined in previous PPF clinical trials is not required prior to enrolment)
• Stable dose of mycophenolate for the preceding 3 months, with a minimum total daily dose of 1,500mg for mycophenolate mofetil or 1080mg for mycophenolate sodium
• Clinically stable for the preceding 6 weeks (did not require addition of corticosteroids for AE-ILD, or any other reason for urgent hospitalization).

Exclusion Criteria:

• Diagnosis of IPF
• Contraindication to treatment with nerandomilast as determined by the treating physician
• FVC < 45% or DLCO < 25% based on last PFT (must be performed within 3 months of screening)
• Use of systemic prednisone > 10 mg/day for > 2 weeks within 3 months of screening (initiation of prednisone during the study is permitted if considered clinically indicated in the opinion of the treating physician)
• Use of azathioprine, cyclophosphamide, rituximab, and/or tocilizumab within 3 months of screening (initiation of azathioprine, cyclophosphamide, rituximab, and/or tocilizumab during the study is permitted if considered clinically indicated in the opinion of the treating physician)
• Use of pirfenidone and/or nintedanib within 6 weeks of screening (initiation of nintedanib and/or pirfenidone during the study is permitted if considered clinically indicated in the opinion of the treating physician)
• Significant emphysema (> 10% volume on HRCT or FEV1/FVC < lower limit of normal)
• Expected survival < 6 months as determined by the treating physician