Sildenafil Effect on Digital Ulcer Healing in sClerodErma SEDUCE STUDY

Inclusion Criteria:

• Patient with systemic sclerosis (ScS) according to the classification criteria of the American College of Rheumatology or of "LeRoy" and "Medsger".
• ScS patient with at least one ongoing ischaemic hand digital ulcer at baseline (see below the eligibility conditions of a digital ulcer).
• Patient must have provided written informed consent prior to enrolment. Patient agrees to come to the follow up visits inside the protocol specified range.
• Relative to each DU: DU must be beyond the proximal interphalangeal joint, on finger surface, of ischemic origin according to the physician, and not over subcutaneous calcifications or bone relief.

Exclusion Criteria:

• PAH requiring PDE5 inhibitors or prostacyclin history of stroke, myocardial infarction or life threatening arrhythmia within the last 6 months
• severe cardiac failure (NYHA IV) or unstable angina within the last 6 months.
• hereditary degenerative retinal disorders non-arteritic anterior ischemic optic neuropathy or untreated proliferative diabetic retinopathy
• uncontrolled diabetes mellitus
• Patient with known severe lung obstructive disease (FEV1<70% on last available pulmonary function tests).
• severe hepatic impairment
• Patient with known impairment of renal function (serum creatinine > 2.5 ULN).
• Patient with severe malabsorption or any severe organ failure (e.g., lung, kidney) or any life-threatening condition.
• Patient who has had surgical sympathectomy performed in the previous 12 months.
• Patient with a history of upper extremity deep vein thrombosis or lymphedema within the previous 3 months.
• Patient participating in a clinical trial or having participated in a clinical trial within the previous 3 months.
• Patient having received a treatment with sildenafil for digital ulcers or pulmonary arterial hypertension within 3 months prior to inclusion.
• Patient having received a treatment with parenteral prostanoids (prostaglandin E, epoprostenol, treprostinil sodium or other prostacyclin analogs) within 3 months prior to inclusion.
• Patient having received a treatment with inhaled or oral prostanoids one month prior to inclusion.
• Patient with previous intolerance or allergy to PDE5 inhibitors or a history of multiple clinically significant allergies.
• Pregnant or lactating female.
• Patient with uncontrolled tachyarrhythmias or bradyarrhythmias, or placement of pacemaker or implantable defibrillator within 60 days prior to randomization.
• Patient with hemodynamic instability or systolic arterial pressure less than 90 mmHg and/or symptomatic orthostatic hypotension.
• Patient receiving all forms of prostacyclin or nitrates or nitric oxide donors in any form including Nicorandil.
• Patient receiving potent inhibitors of CYP3A4 such as ketoconazole, itraconazole, ritonavir.
• Patient with any condition that prevents compliance with the protocol or adhering to therapy.
• Patient who has donated blood during the previous month or intends to donate blood or blood products during the study or for one month following completion of the study.
• Patient under guardianship (including curators) or deprived of liberty.
• Patient presenting with an anatomic malformation of penis (such as an angulation, sclerosis of erectile tissue or "Lapeyronie's disease").
• Patient presenting with a disease which predisposes to priapism (such as sickle-cell disease, myeloma or leukemia).
• Patient presenting with at least one digital ulcer meeting the exclusion criteria (see below).
• Relative to each DU:
• Digital ulcer due to conditions other than scleroderma.
• Non ischaemic digital ulcer.
• Infected digital ulcer requiring systemic antibiotherapy.
• Digital ulcer requiring urgent surgery.