• Subject gives voluntary informed consent to participate in the study.

• Subject is ≥18 years of age, inclusive, at the time of signing informed consent.

• Subject has radiological evidence of pulmonary fibrosis of \>10% extent on an HRCT scan in the previous 12 months (confirmed by central review).

• Subject has a diagnosis of PPF (other than IPF) that fulfills at least 1 of the following criteria for progression within 24 months of screening despite standard treatment of ILD, as assessed by the Investigator:

∙ Clinically significant decline in % predicted FVC based on ≥10% relative decline

‣ Marginal decline in % predicted FVC based on ≥5% to \<10% relative decline combined with worsening of respiratory symptoms

‣ Marginal decline in % predicted FVC based on ≥5% to \<10% relative decline combined with increasing extent of fibrotic changes on chest imaging

‣ Worsening of respiratory symptoms as well as increasing extent of fibrotic changes on chest imaging

• FVC ≥45% predicted at Screening (confirmed by central review).

• Subjects must be on 1 of the following:

∙ On nintedanib or pirfenidone for ≥90 days prior to Baseline and in the Investigator's opinion, are planning to continue treatment through the study

‣ Not on treatment with nintedanib or pirfenidone for ≥90 days prior to Baseline and in the Investigator's opinion, not planning to initiate either treatment during the study.

• Concomitant use of both nintedanib and pirfenidone is not permitted.

• Subjects treated with immunosuppressive agents (eg, mycophenolate, methotrexate, azathioprine, oral corticosteroids, rituximab) need to be on treatment for at least 120 days prior to Baseline and, in the Investigator's clinical opinion, must be refractory to treatment.

• Women of childbearing potential must be non-pregnant (as confirmed by a urine pregnancy test at Screening and Baseline) and non-lactating, and will agree to do 1 of the following:

∙ Abstain from intercourse (when it is in line with their preferred and usual lifestyle)

‣ Use 2 medically acceptable, highly effective forms of contraception for the duration of the study, and at least 30 days after discontinuing study drug.

• i. Medically acceptable, highly effective forms of contraception can include approved hormonal contraceptives (oral, injectable, and implantable) and barrier methods (such as a condom or diaphragm) when used with a spermicide.

• Women who are successfully sterilized (including hysterectomy, bilateral salpingectomy, or bilateral oophorectomy) or postmenopausal (defined as amenorrhea for at least 12 consecutive months) are not considered to be of reproductive potential.

• Males with a partner of childbearing potential must agree to use a condom for the duration of treatment and for at least 48 hours after discontinuing study drug.

⁃ In the opinion of the Investigator, the subject is able to communicate effectively with study personnel, and is considered reliable, willing, and likely to be cooperative with protocol requirements, including attending all study visits.