ATG-GCSF in New Onset Type 1 Diabetes

Inclusion Criteria:

   - Must be > 12 years < 46

   - Must have a diagnosis of T1D for less than 100 days at randomization

   - Willing to provide Informed Consent or have a parent or legal guardian provide
   informed consent if the subject is <18 years of age

   - Positive for at least one islet cell autoantibody; glutamic acid decarboxylase 65
   (GAD65A), Insulin micro IAA (mIAA), if obtained within 10 days of the onset of insulin
   therapy, islet antigen 2 (IA-2A), Islet Cell Antigen (ICA), or zinc transporter 8
   (ZnT8A)

   - Must have stimulated C-peptide levels = 0.2 pmol/ml measured during a mixed meal
   tolerance test (MMTT) conducted at least 21 days from diagnosis of diabetes and within
   one month (37 days) of randomization

   - Must be Epstein-Barr virus (EBV PCR) negative within two weeks of randomization if EBV
   seronegative at screening

   - Be at least 6 weeks from last live immunization

   - Participants are required to receive killed influenza vaccination at least 2 weeks
   prior to randomization when vaccine for the current or upcoming flu season is
   available

   - Be willing to forgo vaccines during the treatment period and for 3 months following
   last dose of study drug

   - Be willing to comply with intensive diabetes management

Exclusion Criteria:

   - Be immunodeficient or have clinically significant chronic lymphopenia: (Leukopenia (<
   3,000 leukocytes /µL), neutropenia (<1,500 neutrophils/µL), lymphopenia (<800
   lymphocytes/µL), or thrombocytopenia (<100,000 platelets/µL).

   - Have active signs or symptoms of acute infection at the time of randomization

   - Have evidence of prior or current tuberculosis infection as assessed by purified
   protein derivative (PPD), interferon gamma release assay (IGRA) or by history

   - Be currently pregnant or lactating, or anticipate getting pregnant within the two year
   study period

   - Require use of other immunosuppressive agents including chronic use of systemic
   steroids

   - Have evidence of current or past human immunodeficiency virus (HIV), Hepatitis B or
   Hepatitis C infection

   - Have any complicating medical issues or abnormal clinical laboratory results that may
   interfere with study conduct, or cause increased risk to include pre-existing cardiac
   disease, chronic obstructive pulmonary disease (COPD), sickle cell disease,
   neurological, or blood count abnormalities

   - Have a history of malignancies other than skin

   - Evidence of liver dysfunction with aspartate aminotransferase (AST) or alanine
   transaminase (ALT) greater than 3 times the upper limits of normal

   - Evidence of renal dysfunction with creatinine greater than 1.5 times the upper limit
   of normal

   - Vaccination with a live virus within the last 6 weeks

   - Current or ongoing use of non-insulin pharmaceuticals that affect glycemic control
   within prior 7 days of screening

   - Active participation in another T1D treatment study in the previous 30 days

   - Prior treatment with abatacept or anti-cd3

   - Known allergy to GCSF or ATG

   - Prior treatment with ATG or known allergy to rabbit derived products

   - Any condition that in the investigator's opinion may adversely affect study
   participation or may compromise the study results