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

This is a 2-Part study with Part A, a double-blind, randomized, placebo-controlled, PoC study to evaluate the efficacy, safety, and tolerability of efzofitimod in patients with SSc-ILD. The primary objective of the study is to evaluate the PoC for efficacy in a population with SSc-ILD. While improvement of ILD is the outcome of interest, the study will also evaluate changes in the skin. After initial screening (up to 4 weeks), approximately 25 eligible participants will be randomized 2:2:1 to 1 of 2 active (experimental) dose arms or placebo, administered every 4 weeks up to and including Week 20. Part B is an optional open-label extension to Part A in which participants can receive 450 mg efzofitimod every 4 weeks for 6 doses.


Eligibility Criteria:
Inclusion Criteria:

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.

Exclusion Criteria:

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