DESIGNATE siplizumab dose-finding study in recent-onset T1D
What this study tests
Terminated Phase 1/2 anti-CD2 antibody study in recent-onset T1D. Enrollment was held after greater-than-anticipated lymphocyte depletion; the partner then stopped development of siplizumab in autoimmunity.
Editorial review: .
Registry checked: 2026-09-17. Registry’s own update: 2026-07-28.
Most recent recorded citation date: 2026-07-28. Only explicit date metadata is included; an undated citation may be newer. This does not mean every claim was reviewed on that date.
Trial status, labels and access can change between reviews. How we review the evidence · How to read the evidence
Evidence at a glance
- Who can enter the study?
- People aged 8-45 diagnosed with T1D within roughly 18 months; adults were to enrol first. See registry for full criteria. Registered eligibility ↗Enrollment criteria describe who may enter. They do not establish who was analyzed or the denominator for a reported result.
- Reported benefit and results
- Eight adults were randomized, seven received siplizumab, and six had the two consecutive doses and viable samples required for the primary per-protocol analysis, versus 160 participants planned. Three of six met the composite T-cell phenotype-response definition (one at each of 0.08, 0.12, and 0.18 mg/kg; none at 0.22 mg/kg). This is an immune-phenotype signal, not clinical efficacy; the C-peptide and insulin-use outcomes were not posted and planned analyses were not produced because the sample was too small. There were no deaths or serious adverse events among the seven treated adults, but all seven had decreased CD4 lymphocytes recorded as a nonserious adverse event. The study had been held for greater-than-anticipated lymphodepletion before the pharmaceutical partner ended siplizumab development in autoimmunity.Read the result sources and their limitations →
- Important harms
- Read the reported results, safety discussion and original sources. A separate harms summary is not available; this does not establish safety.
- Research access and approval
- Study regions: United States. A trial listing does not establish product approval or current recruitment at a particular site. Check the study’s current entry requirements.
- What remains uncertain?
- Read the full discussion and original sources for study limitations. Planned endpoints and completion dates are not results.
Research status alone does not establish approval, clinical benefit or local availability.
Primary endpoints
- Number of participants with the specified T-cell phenotype response by week 12
The full picture
This record has no longer discussion. Use the study criteria, reported results and original sources on this page to assess what is known and what remains unresolved.
Sources
- [1]NCT05574335: DESIGNATE siplizumab in T1D · Trial registry · 2026-07-28 — TERMINATED; actual n=8 randomized and n=7 treated. Results first posted 2026-07-28. The sponsor-posted stop reason cites greater-than-anticipated lymphodepletion and cessation of the autoimmune development programme.