Subjects from the AG-CLI-0206 phase 3 study that received AMG0001 will be eligible for the AG-CLI-0206-LTFU study

The study is designed to assess the long term safety of subjects who have been treated in the phase 3 study with AMG0001. A health questionnaire will be used to collect specific information from the subject every 6 months. Only those subjects that were randomized in the AG-CLI-0206 study and who received AMG0001 are eligible to participate in this long term follow-up study. Subjects that received placebo will not be eligible for participation in this study.

Inclusion Criteria:

• Subjects who have been treated with AMG0001 in the AG-CLI-0206 study.
• Subjects who have provided consent for this long term follow-up study either directly or through a legally authorized representative.
• Subjects who have provided a release of information to the sponsor.

Exclusion Criteria:

• Subjects who were not enrolled in the AGCLI-0206 study.
• Subjects who enrolled in AG-CLI-0206 and who were not treated with AMG0001.
• Subjects who have not provided consent to this long term follow-up study either directly or through a legally authorized representative.
• Subjects who have not provided a release of information for the Sponsor to contact them directly via phone, email and/or mail.

Subjects with critical limb ischemia who have previously been treated with AMG0001 in the AG-CLI-0206 study.