The International Diabetes Closed Loop (iDCL) Trial: Clinical Acceptance of the Artificial Pancreas

After consent is signed, eligibility will be assessed. Eligible participants not currently
using an insulin pump and Dexcom CGM with minimum data requirements will initiate a run-in
phase of 2 to 8 weeks that will be customized based on whether the participant is already a
pump or CGM user. Participants who skip or successfully complete the run-in will be randomly
assigned 2:1 to the use of closed-loop control (CLC group) using t:slim X2 with Control-IQ
Technology vs. SAP for 6 months.

Inclusion Criteria:

1. Clinical diagnosis, based on investigator assessment, of type 1 diabetes for at least
one year and using insulin for at least 1 year.

2. Familiarity and use of a carbohydrate ratio for meal boluses.

3. Age ≥14.0 years old.

4. For females, not currently known to be pregnant. If female and sexually active, must
agree to use a form of contraception to prevent pregnancy while a participant in the
study. A negative serum or urine pregnancy test will be required for all females of
child-bearing potential. Participants who become pregnant will be discontinued from
the study. Also, participants who during the study develop and express the intention
to become pregnant within the timespan of the study will be discontinued.

5. For participants <18 years old, living with one or more parent/legal guardian
knowledgeable about emergency procedures for severe hypoglycemia and able to contact
the participant in case of an emergency.

6. Willingness to suspend use of any personal CGM for the duration of the clinical trial
once the study CGM is in use.

7. Investigator has confidence that the participant can successfully operate all study
devices and is capable of adhering to the protocol.

8. Willingness to switch to lispro (Humalog) or aspart (Novolog) if not using already,
and to use no other insulin besides lispro (Humalog) or aspart (Novolog) during the
study.

9. Total daily insulin dose (TDD) at least 10 U/day.

10. Willingness not to start any new non-insulin glucose-lowering agent during the course
of the trial.

Exclusion Criteria

1. Concurrent use of any non-insulin glucose-lowering agent other than metformin
(including GLP-1 agonists, Symlin, DPP-4 inhibitors, SGLT-2 inhibitors,
sulfonylureas).

2. Hemophilia or any other bleeding disorder.

3. A condition, which in the opinion of the investigator or designee, would put the
participant or study at risk.

4. Participation in another pharmaceutical or device trial at the time of enrollment or
during the study.

5. Employed by, or having immediate family members employed by Tandem Diabetes Care, Inc.
or TypeZero Technologies, LLC, or having a direct supervisor at place of employment
who is also directly involved in conducting the clinical trial (as a study
investigator, coordinator, etc.); or having a first-degree relative who is directly
involved in conducting the clinical trial.