CNP-103 in Adolescent and Adult Subjects Ages 12-35 With Recently Diagnosed (Within 6 Months) Stage 3 Type 1 Diabetes (T1D)

Participants who are willing and able to provide Institutional Review Board (IRB) approved written informed consent and privacy language as per national regulations.

Men and non-pregnant, non-breast-feeding women ages 12-35 years inclusive.

Documented diagnosis of Stage 3 T1D within 180 days prior to study enrollment according to American Diabetes Association (ADA) criteria.

Participants must be on standard of care diabetes management including insulin therapy as a routine and also consisting of a nutrition plan, regular exercise, or other relevant specialty care as required on a patient-by-patient basis.

Participants with a peak stimulated C-peptide of >0.2 nmol/L measured from a screening mixed meal tolerance test (MMTT).

Participants with an episode of diabetic ketoacidosis (DKA) must have a MMTT performed no sooner than 2 weeks after resolution of the DKA event to have a qualifying C-peptide reading.

Participants on systemic corticosteroids or any medication used to treat the symptoms of T1D (other than insulin) must undergo a washout period of at least two weeks prior to enrollment and must agree to use a non-steroid alternative throughout the trial, if necessary, for any disorder requiring corticosteroids. In addition, participants must be on a stable dose of any other medications, other than insulin, for a minimum of 1 month prior to enrollment and must agree not to increase their dose from the Screening Visit through the End of Study Visit unless reviewed and approved by the medical monitor and the principal investigator.

Female participants of non-childbearing potential (e.g., surgical sterilization, no menses for a year).

Women of childbearing potential (WOCBP) who have agreed not to become pregnant during the study, have a negative pregnancy test at Screening Visit, and agree to use 1 highly effective form of birth control starting at initial screening and continuing throughout the entire study to Day 365.

Female participants who agree to not breastfeed starting at initial Screening and throughout the entire study to Day 365.

Female participants who agree to not donate ova, including autologous, starting at initial Screening and throughout the entire study to Day 365.

Male participant and with a spouse or partner of childbearing potential, who themselves and their spouse or partner agree to practice an effective form of birth control as discussed with the study doctor or study staff starting at Screening and throughout the entire study to Day 365.

Participants must weigh >35 kg at Screening for Cohort 1 (100 mg) and Cohort 2 (300 mg); participants must weigh >50 kg at Screening for Cohort 3 (600 mg).

Body mass index (BMI):

1. Participants 12-17 years: BMI Z-Score within 5th and 95th percentile based on participant's age (e.g., Baylor College of Medicine Age-based Pediatric Growth Reference Charts: BMI Z-Score and Percentile Calculator)
2. Participants 18-35 years: 18.0-30.0 (not inclusive)