The International Diabetes Closed Loop (iDCL) Trial: Protocol 1


About this study

The objective of the study is to assess the efficacy and safety of home use of a Control-to-Range (CTR) closed-loop (CL) system.

Participation eligibility

Participant eligibility includes age, gender, type and stage of disease, and previous treatments or health concerns. Guidelines differ from study to study, and identify who can or cannot participate. There is no guarantee that every individual who qualifies and wants to participate in a trial will be enrolled. Contact the study team to discuss study eligibility and potential participation.

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. Use of an insulin pump for at least 6 months
  3. Age ≥14 years old
  4. HbA1c level <10.5% at screening
  5. For females, not currently known to be pregnant
  6. Willingness not to add glucose-lowering agents (such as Pramlintide, Metformin, GLP-1 analogs, SGLT2 inhibitors) during the study
  7. Willingness, if not assigned to the closed-loop group, to avoid use of any closed-loop control system for the duration of the clinical trial
  8. Willingness to suspend use of any personal CGM for the duration of the clinical trial once the unblinded study CGM is in use
  9. Willingness to establish network connectivity on at least a weekly basis either via local Wifi network or via a study-provided cellular service
  10. Currently using no insulins other than one of the following rapid-acting insulins at the time of enrollment: insulin lispro (Humalog), insulin aspart (Novolog), or insulin glulisine (Apidra)
  11. Investigator has confidence that the subject can successfully operate all study devices and is capable of adhering to the protocol
  12. For subjects less than 18 years old, living with one or more parent/legal guardian (referred to subsequently as diabetes care partner) committed to participating in study training for emergency procedures for severe hypoglycemia and able to contact the subject in case of an emergency

Exclusion Criteria:

  1. Medical need for chronic acetaminophen
  2. Use of any glucose-lowering agent (such as Pramlintide, Metformin, GLP-1 analogs, SGLT2 inhibitors) in the 3 months prior to enrollment
  3. Hemophilia or any other bleeding disorder
  4. A condition, which in the opinion of the investigator or designee, would put the participant or study at risk including any contraindication to the use of any of the study devices per FDA labeling
  5. Participation in another pharmaceutical or device trial at the time of enrollment or during the study
  6. Use of a closed-loop system within the last month prior to enrollment
  7. Employed by, or having immediate family members employed by TypeZero Technologies, LLC

Participating Mayo Clinic locations

Study statuses change often. Please contact the study team for the most up-to-date information regarding possible participation.

Mayo Clinic Location Status Contact

Rochester, Minn.

Mayo Clinic principal investigator

Yogish Kudva, M.B.B.S.

Closed for enrollment

Contact information:

Shelly McCrady-Spitzer M.S.


More information


Publications are currently not available

Study Results Summary

Not yet available

Supplemental Study Information

Not yet available


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