• Participants must have SSc, as defined using the 2013 American College of Rheumatology/European League Against Rheumatism criteria

• If participant is on a non-excluded immunosuppressive therapy (e.g. mycophenolate, methotrexate, azathioprine, etc.) the dose should be stable for \> 2 months at the time of screening

• Women of childbearing potential must:

‣ If sexually active, have used, and agree to use, highly effective contraception without interruption, for at least 28 days prior to starting investigational product, during the study (including dose interruptions), and for 17 weeks (119 days) after discontinuation of study treatment

⁃ Refrain from breastfeeding a child or donating blood, eggs, or ovum for the duration of the study and for at least 17 weeks (119 days) after the last dose of study treatment

• Male participants must:

‣ Agree to use a condom, defined as a male latex condom or nonlatex condom NOT made out of natural (animal) membrane (e.g., polyurethane), during sexual contact with a pregnant female or a female of childbearing potential while participating in the study, during dose interruptions, and for at least 17 weeks (119 days) following investigational product discontinuation, even if he has undergone a successful vasectomy

⁃ Refrain from donating blood or sperm for the duration of the study and for 17 weeks (119 days) after the last dose of study treatment

• Must agree to not participate in any other study of investigational drugs/devices while enrolled in this study