This is a randomized, placebo controlled, phase I/II trial. Potential subjects will be screened via a 4 hour mixed meal tolerance test to assess residual beta cell (C-peptide) function. If the C-peptide level at any time is ≥ 0.1 pmol/ml, and the subject meets the additional inclusion and exclusion criteria, they will be eligible for randomization and enrollment. The study will be randomized 2:1 such that 17 subjects will receive active therapy and 8 will receive placebo. Subjects must receive Thymoglobulin®/ Neulasta® or placebo within 8 weeks of randomization. Thymoglobulin® (2.5mg/kg)/placebo will be given as 0.5 mg/kg IV on day 1 and 2 mg/kg on day 2. Six doses of Neulasta® (6mg/dose)/placebo will be given as standard of care every 2 weeks, with the first dose given prior to discharge after the Thymoglobulin® infusion. Complete metabolic panel (CMP) and complete blood count (CBC) will be done at the screening visit, just prior to study drug initiation, daily during the Thymoglobulin® infusion admission, and at follow up visits. Following discharge, daily phone calls will be made to the subjects during the first 5 days of therapy and weekly thereafter. In addition, weekly phone calls for the month following completion of therapy will be used to document adverse reactions. Thereafter calls will be made every two weeks.