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type1.science

Ustekinumab (IL-12/23 p40 blocker)

Janssen / Johnson & Johnson (Stelara; repurposed)

A repurposed psoriasis/Crohn's antibody that blocks the shared IL-12/IL-23 p40 subunit. A 2024 adolescent phase-2 trial met its 12-month C-peptide endpoint with good tolerability, and a separate adult phase-2/3 trial is active but not recruiting. It is not approved for T1D.

On the horizonModerate evidenceimmunotherapyrepurposedmonoclonal-antibodyil-12il-23th17beta-cell-preservation

The scorecard

Delay of onset45

Has not shown prevention of stage-3 onset, but in recent-onset adolescents preserved stimulated C-peptide at 12 months; the active adult UST1D2 trial is testing whether that signal generalizes.[1]

Durability35

Published evidence is 12-month preservation only; durability after treatment and clinical outcomes such as insulin dose remain open.[1]

Safety70

The adolescent trial reported no increase in adverse events, and the drug has a long non-diabetes safety history, but T1D use remains investigational.[1]

Stage breadth30

Current T1D evidence is new-onset stage 3 only; no stage-1/2 prevention result yet.[2]

Access & cost20

Already marketed for immune diseases, but no T1D indication; practical access is trial/off-label only and biologic pricing would be a barrier.[3]

Editor’s take

Ustekinumab is one of the cleaner newer immune signals: a named pathway, an approved drug, and a positive randomized adolescent trial without obvious safety noise. The honest caveat is that this is preservation after diagnosis, not proven prevention, and the field needs the larger UST1D2 readout before treating it as more than a promising repurposing candidate.

The full picture

Why it belongs here

Ustekinumab blocks the shared p40 subunit of IL-12 and IL-23, two cytokine pathways that help shape Th1 and Th17 immune responses. In T1D, the rationale is not to replace insulin, but to reduce the inflammatory T-cell program that keeps damaging beta cells after diagnosis.

Evidence

The strongest published signal is the 2024 adolescent randomized phase-2 trial: 72 young people aged 12-18 with recent-onset T1D received ustekinumab or placebo. At 12 months, stimulated C-peptide was 49% higher in the ustekinumab group, and the study reported no increase in adverse events.1

That is a meaningful beta-cell preservation signal, but not a cure and not yet prevention. The result is short-term, stage-3, and needs the active UST1D2 phase-2/3 adult study before it can be ranked alongside the stronger, multi-trial candidates.2

References

  1. Tatovic D, et al. Ustekinumab for type 1 diabetes in adolescents: a multicenter, double-blind, randomized phase 2 trial. Nature Medicine (2024). https://doi.org/10.1038/s41591-024-03115-2 ↩

  2. National Library of Medicine. Clinical Phase II/III Trial of Ustekinumab to Treat Type 1 Diabetes (UST1D2). ClinicalTrials.gov NCT03941132. https://clinicaltrials.gov/study/NCT03941132 ↩

Coming soon

ETA · Adult phase-2/3 UST1D2 active; completion estimated 2026

  • →Adult UST1D2 phase-2/3 trial readout · completion estimated 2026

Sources

  1. [1]Ustekinumab for type 1 diabetes in adolescents: a multicenter, double-blind, randomized phase 2 trial · peer-reviewed · 2024-07-30 — PMID 39079992. Seventy-two adolescents aged 12-18 with recent-onset T1D; stimulated C-peptide was 49% higher at 12 months (P=0.02).
  2. [2]Clinical Phase II/III Trial of Ustekinumab to Treat Type 1 Diabetes (UST1D2) · registry · 2025-02-24 — University of British Columbia. Active, not recruiting; estimated n=66; adults 18-35 with recent-onset T1D; completion estimated November 2026.
  3. [3]STELARA (ustekinumab) prescribing information · regulatory · 2022-07-29 — FDA label for approved non-T1D indications; no T1D indication.