The primary objective of the study is to demonstrate the superiority of XRP0038/NV1FGF over placebo in the prevention of major amputation above the ankle of the treated leg or of death from any cause, whichever comes first, in critical limb ischemia (CLI) patients with skin lesions.

The secondary objectives of the study are to evaluate:

• The efficacy of XRP0038/NV1FGF versus XRP0038/NV1FGF placebo for delaying the time to death.
• The safety of XRP0038/NV1FGF in the study population

Inclusion Criteria:

• Having peripheral artery disease at the stage of Critical Limb Ischemia (CLI) with skin lesions (either ulcer(s) or gangrene)
• With objective evidence of CLI such as ankle systolic pressure less than 70 mmHg and/or toe systolic pressure less than 50 mmHg or TcPO2 less than 30 mm Hg
• Unsuitable for standard revascularization of his/her peripheral arterial disease
• Having a negative screening for cancer

Exclusion Criteria:

• Previous major amputation on the leg to be treated or planned major amputation within the first month following randomization
• Known Buerger's disease
• Successful lower extremity revascularization procedure within 3 months prior randomization
• Uncontrolled blood pressure defined as SBP≥ 180 mmHg or DBP ≥110 mmHg despite adequate antihypertensive treatment
• Acute cardiovascular events within 3 months prior to randomization
• Active proliferative retinopathy and severe macular oedema
• Previous or current history of malignant disease within the past 5 years
• Previous treatment with systemic angiogenic factors or with stem cells therapy
• Pregnant or breast-feeding women or women of childbearing potential not protected by an effective contraceptive method of birth control

The above information is not intended to contain all considerations relevant to a patient's potential participation in a clinical trial.