MELD-ATG: Phase II, Dose Ranging, Efficacy Study of Anti-thymocyte Globulin (ATG) Within 6 Weeks of Diagnosis of Type 1 Diabetes (T1D)

Inclusion Criteria:

• has given written informed consent to participate; or have a parent or legalguardian provide written informed consent. Individual under the age of consent willbe asked to assent to trial participation

• be aged > 5 years to < 25 years at written informed consent/assent

• have been diagnosed with T1d within 3-9 weeks of planned treatment day 1

• have random C-peptide levels > 200 pmol/L measured at screening, as tested centrally

• have 1 or more diabetes-related autoantibody (GADA, IA-2A or ZnT8A) present atscreening, as tested centrally

• will be > 6 weeks form last live immunisation at planned treatment day 1 and bewilling to forgo live vaccines during the trial until 6 months post treatment

• be willing to comply with intensive diabetes management

Exclusion Criteria:

• Type 2 diabetes

• Evidence of prior or current tuberculosis (TB) infection

• Clinically significant abnormal full blood count (FBC), renal function or liverfunction at screening

• Requiring use of other immunosuppressive or immunomodulation agents, includingchronic use of systemic steroids

• any active chronic infections at screening, or any active acute or chronicinfections at baseline or on treatment day, which would contraindicate anyadditional immunosuppression

• seropositive for human immunodeficiency virus (HIV),hepatitis B of hepatitis Cinfection at screening

• positive for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) based onlocal testing regimen

• unwilling to use appropriate contraception if sexually active during the trial, fromdate of written informed consent until completion of the 12-month follow-up visit

• any history of malignancies, other than skin

• current or ongoing use of non-insulin pharmaceuticals that effect glycaemic control

• active participation in another T1D treatment interventional trial in the previous 30 days prior to screening ( excluding treatment with insulin)

• any prior treatment with ATG, Abatacept or Anti-CD3 monoclonal antibody (Anti-CD3)

• known allergy to ATG or to similar products

• any condition, complicating medical issues, or abnormal clinical laboratory resultsthat the investigator judges may adversely affect trial conduct, cause increasedrisk to the participant, or compromise the trial results