Study to Evaluate the Efficacy, Safety, and Tolerability of Efzofitimod in Patients With Systemic Sclerosis (SSc)-Related Interstitial Lung Disease (ILD) (SSc-ILD)

Open to people ages 18 years and up

1. Diagnosis of SSc based on ACR/ EULAR criteria (2013)

2. Overall duration of SSc < 48 months from the first non-Raynaud symptom manifestation OR

   If overall duration of SSc > 48 and < 72 months from the first non-Raynaud symptom manifestation, then with presence of any of the following:

   1. Any 1 laboratory marker for active disease:
      • C-reactive protein ≥ 0.6 mg/dL (≥ 6 mg/L)
      • Erythrocyte sedimentation rate ≥ 28 mm/hr
      • Platelet count ≥ 330 × 10e9/L (330,000/μL) OR
   2. Clinically significant decline in FVC % predicted (%pred) based on ≥ 5% relative decline over the preceding one year OR
   3. An increase ≥ 3 in the mRSS over 6 months or less
3. HRCT obtained at the Screening Visit or within the 3 months prior to Screening consistent with SSc-ILD (adjudicated by a central reader) AND with pulmonary involvement > 10%
4. Clinical presentation at Screening consistent with lcSSc (up to 40% of patients) or dcSSc
5. MMF of ≥ 2 gm/day (or equivalent doses of other mycophenolate based compounds) for 6 months OR When documented intolerance to mycophenolates, treatment with adequate doses and duration of an alternate immunosuppressant with a stable dose for the 4 weeks prior to baseline. The use of an alternate immunosuppressant must be discussed with the Medical Monitor.

1. Pulmonary disease with FVC %pred ≤ 45% OR DLco %pred ≤ 30%; FEV1/FVC ratio < 0.7
2. Participants with pulmonary artery hypertension on parenteral therapy or with clinical evidence of right heart failure
3. HRCT obtained in the 3 months prior to Screening consistent with other confounding pathology.
4. Treatment with corticosteroids (> 10 mg/day of prednisone or equivalent) within 2 weeks prior to baseline
5. Treatment with more than 1 immunosuppressant (e.g., MMF, methotrexate [MTX], azathioprine [AZA], or leflunomide)
6. Any previous treatment with any of the following: rituximab, intravenous immune globulin (IVIG), tocilizumab, cyclophosphamide, pirfenidone, tyrosine-kinase inhibitors (e.g., imatinib, nilotinib, dasatinib)
7. Rheumatic autoimmune disease other than SSc, Is an active, heavy smoker of tobacco/nicotine-containing products
8. History of (anti-Jo-1) anti-synthetase syndrome or Jo-1 positive at Screening