A Study of the Safety and Efficacy of Injectable Thymosin Beta 4 for Treating Acute Myocardial Infarction

This is a double-blind, placebo controlled, parallel-group, dose finding study. Eligible
subjects will be randomized to receive one of two doses of RGN-352 or matching placebo with
an equal allocation ratio (i.e., 1:1:1). Approximately 75 subjects will be randomized to
study treatment to achieve at least 60 evaluable subjects with 20 to 25 subjects per group.
Subjects will be randomized to receive one of two RGN-352 doses of 1200 mg, or 450 mg, or
placebo, administered iv by iv push daily for the first 3 consecutive days and weekly for 4
consecutive weeks. Study subjects will undergo cardiac angiography to assess initial
coronary artery patency and Thrombolysis In Myocardial Infarction flow grade both pre- and
post-PCI angioplasty. A total of 7 doses will be administrated over the treatment period.
The first dose of either RGN-352 or placebo will be administered to randomized subjects
following PCI angioplasty and specifically within 30 minutes after balloon deflation, with a
further 2 doses. The remaining 4 doses will be given weekly for 4 consecutive weeks.
Follow-up is on Months 2, 4, and 6.

Inclusion Criteria:

1. Male and female subjects

2. Negative urine pregnancy test at Screening

3. An electrocardiogram

4. First acute anterior MI

5. Baseline angiography

6. Onset of chest pain symptoms to initial PCI angioplasty time is 2 to 6 hours

7. Written informed consent reviewed and signed by the subject or legally authorized
representatives

Exclusion Criteria:

1. Intention to treat subject with thrombolytic therapy following assertion of TIMI flow
0 or 1 during qualifying angiogram

2. History of Myocardial infarctionI or congestive heart failure

3. Non-atherosclerotic etiology of acute myocardial infarction

4. Cardiogenic shock (systolic blood pressure <90 despite adequate left ventricle
filling pressure or requiring catecholamines) or other hemodynamic instability at
baseline

5. Further transcatheter or surgical revascularization, e.g., coronary artery bypass
graft planned per baseline angiogram

6. Lactating women

7. Past or present evidence of malignancy

8. Women who have had menarche but have not completed menopause, have not been
surgically sterilized (bilateral tubal ligation or hysterectomy), do not have a
partner with documented sterility (including vasectomy), or are not using adequate
contraception (combined hormonal or double-barrier method of contraception, or sexual
abstinence are the only methods of contraception acceptable for this study)

9. Ongoing infectious disease including human immunodeficiency virus (HIV) and hepatitis

10. Clinically significant respiratory, renal, metabolic, liver, central nervous system
or other comorbid disease, except current cardiovascular disease