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For adults age 18 – 45 years who have been diagnosed with type 1 diabetes in the past 18 months, the DESIGNATE study will test whether a new drug called siplizumab will reduce or block the T-cells that attack the insulin-producing beta cells.

The goal of this study is to see how the experimental study drug, siplizumab, can block or weaken the cells that attack beta cells in the pancreas. This would allow the beta cells to continue to function and produce insulin.

Siplizumab is a new drug which targets the immune pathway that may block or reduce certain T cells that attack the beta cells in the pancreas. This study is investigating the safety and efficacy of different doses of siplizumab that will induce this change. There are four treatment groups in the study, each testing a different dose of siplizumab. You cannot choose your treatment group. There is no placebo group, so everyone will receive medication.

DESIGNATE is a one-year study. During the first three months, there are 12 weekly study visits where you will receive an injection of siplizumab and have your health monitored. During the next nine months, you will have four follow-up visits (at weeks 12, 24, 36 and 52). You will receive personalized coaching in diabetes management throughout the year.

Study visits take place at our Clinical Research Center in Seattle and at other sites throughout the US.

Participant Eligibility

You may be eligible to participate if you:
• are 18 – 45 years,
• have been diagnosed with T1D in past the 18 months,
• and are fully vaccinated for COVID-19 and influenza


Katie Bennett
(800) 888-4187

Additional Study Details

Full Study Title
A T Cell Phenotype Signature Driven Dose Finding Study With Siplizumab in Type 1 Diabetes Mellitus

Study ID: SSU00205456
Start Date: 01/27/2023
End Date: 08/31/2026

Stephen Gitelman, MD
Sandra Lord, MD

Accepts Healthy Volunteers?

Study Site(s)

Benaroya Research Institute

1201 9th Ave
Seattle, Washington 98101


Use the link below to send a message to the study coordinator, or call the number above to speak directly with a study representative.

I am interested in this research study.