Stephen Gitelman, MD | University of California San Francisco

University of Alabama at Birmingham | Birmingham, AL

Stanford University and Stanford Children's Health | Stanford, CA

University of California San Francisco | San Francisco, CA

Barbara Davis Center | Aurora, CO

University of Florida | Gainesville, FL

University of Miami | Miami, FL

University of South Florida | Tampa, FL

Emory University School of Medicine | Atlanta, GA

University of Chicago | Chicago, IL

University of Iowa | Iowa City, IA

Joslin Diabetes Center | Boston, MA

University of Minnesota | Minneapolis, MN

Children's Mercy Hospital and Clinics | Kansas City, MO

Columbia University | New York, NY

University of Buffalo MD Pediatrics | Buffalo, NY

Children's Hospital of Philadelphia | Philadelphia, PA

Sanford Health | Sioux Falls, SD

UT Southwestern Medical Center | Dallas, TX

Benaroya Research Institute | Seattle, WA

The primary objective of the DESIGNATE study is to identify a safe, metabolically favorable, dosing regimen for siplizumab in patients with type 1 diabetes mellitus (T1DM) that induces changes in T cell phenotypes observed with alefacept therapy in new-onset T1DM.

Participants will be age 8-45 and within 18 months of T1DM diagnosis.

DESIGNATE is a multicenter, Phase Ib, open-label, siplizumab dose-finding study in new onset T1DM.

Participants will be randomized 1:1:1:1 to one of four possible siplizumab dosing arms. All dosing arms will receive weekly siplizumab doses for a total of 12 weeks. After the completion of treatment, participants will undergo follow-up visits at weeks 12, 24, 36 and 52 which include longitudinal MMTTs. Blood samples for mechanistic analyses will be obtained during the treatment phase and thereafter. Adults aged 18- 45 will be enrolled initially at the study sites.