IMC-S118AI (PPI × PD-1 ImmTAAI)
Immunocore
What it is
Immunocore’s first autoimmune ImmTAAI molecule: a soluble TCR that binds a pre-proinsulin peptide on HLA-A*02:01 beta cells and delivers local PD-1 agonism. A first-in-human Type 1 dose-escalation study is registered. There are no human efficacy results.
Editorial review: .
Most recent recorded citation date: 2026-08-25. 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 behind this assessment
Key evidence notes. Study results, product eligibility and access answer different questions.
- Who was studied?
- Study populations and analysis groups vary. Product age limits alone do not describe who was studied.See the linked studies and their populations →
- Benefit or performance
- Beta-cell preservation: The protocol lists mixed-meal C-peptide AUC at week 25 as a secondary endpoint in the multiple-dose part. That is a planned measure, not a posted preservation result.[1]
- Important harms and treatment burden
- Safety: This is a first-in-human intravenous bispecific. Primary endpoints are adverse events, labs, ECG and dose interruptions over weeks to a year. PD-1 agonism is intended to be local, not systemic immunosuppression, but that safety story is untested in people with T1D.[1]
- Approval and country access
- Country-specific approval and access are not summarized in this record.Approval, trial recruitment, local supply and funding are separate. Check the cited label or access source.
- Follow-up and remaining uncertainty
- Durability: Tissue-tethered PD-1 agonism is designed to quiet attack only at the beta cell, but how long any effect would last after infusions stop is unknown. Follow-up in the registered study runs to about a year, not years off drug.[1]
Research status alone does not establish approval, clinical benefit or local availability. This record cites company or conference reports. Those sources may describe interim findings; their source type is shown in the source list.
Editorial score: calculation and evidence
A weighted editorial judgment on a 0–100 scale, not a probability of success or a measured treatment effect. Higher criterion scores mean more favorable assessments.
Default calculation: 12 × 30 + 10 × 20 + 22 × 20 + 14 × 10 + 20 × 20 = 1540; divide by total weight 100. Unrounded weighted result: 15.4.
The protocol lists mixed-meal C-peptide AUC at week 25 as a secondary endpoint in the multiple-dose part. That is a planned measure, not a posted preservation result.[1]
Tissue-tethered PD-1 agonism is designed to quiet attack only at the beta cell, but how long any effect would last after infusions stop is unknown. Follow-up in the registered study runs to about a year, not years off drug.[1]
This is a first-in-human intravenous bispecific. Primary endpoints are adverse events, labs, ECG and dose interruptions over weeks to a year. PD-1 agonism is intended to be local, not systemic immunosuppression, but that safety story is untested in people with T1D.[1]
HLA-A*02:01 positive people with residual beta-cell function; BMI 18–25 kg/m². ClinicalTrials.gov lists ages 18–45; the later EU CTIS record lists 12–45. Either way this is a genotype- and C-peptide-restricted first-in-human group, not a preview of who could be treated.[2]
Registered Phase 1/1b (NCT07493122; EU CT 2025-524449-28-00). CT.gov remains not-yet-recruiting as of last update 25 March 2026 (live-checked 27 August 2026); estimated start April 2026 has passed. CTIS authorised the trial with an EU start date of 10 August 2026. A start date is not enrollment and not a result.[2]
The full picture
IMC-S118AI is described by Immunocore as its first autoimmune use of the ImmTAAI platform — the same TCR-bispecific idea as Kimmtrak, flipped so that instead of activating T cells against a tumour it tries to quiet T cells that are attacking insulin-producing cells. The molecule recognises a pre-proinsulin peptide presented on HLA-A*02:01 on beta cells and, once tethered there, is designed to agonise PD-1 on nearby pathogenic T cells. That is a tissue-specific down-modulation claim, not proof that people keep making insulin.
The registered first-in-human study (NCT07493122; EU CT 2025-524449-28-00) is a single- and multiple-ascending-dose trial in people with Type 1 diabetes who still have residual beta-cell function. Primary endpoints are safety. Mixed-meal C-peptide AUC at week 25 is secondary in the multiple-dose part. ClinicalTrials.gov still says not yet recruiting (last update 25 March 2026, estimated n=154, ages 18–45, estimated start April 2026 — that date has passed). The later CTIS record is authorised, lists an EU start of 10 August 2026, United Kingdom and Australia, planned n=134, and ages 12–45. A registry authorisation, or a passed estimated start, is not enrollment and not a C-peptide result.
HLA-A*02:01 positivity restricts eligibility and is not universal. BMI 18–25 kg/m² and residual C-peptide further narrow who can join. Do not read a first-in-human protocol as a treatment.
Coming soon
ETA · First-in-human Phase 1/1b. ClinicalTrials.gov still not-yet-recruiting as of 27 August 2026 (last update 25 March 2026; estimated start April 2026 has passed). CTIS lists an EU start of 10 August 2026. No efficacy timeline.
Sources
- [1]Study of IMC-S118AI in Type 1 Diabetes · Trial registry · 2026-03-25 — Phase 1; estimated n=154; still not-yet-recruiting on ClinicalTrials.gov as of last update 25 March 2026 (live-checked 27 August 2026). Estimated start April 2026 has passed without a status change. No results.
- [2]Phase 1/1b study of IMC-S118AI in Type 1 Diabetes (EU CT 2025-524449-28-00) · Trial registry · 2026-08-25 — CTIS status Authorised; EU start 10 August 2026; estimated recruitment start 1 August 2026; countries United Kingdom and Australia; planned n=134 on the EU application.
- [3]Immunocore reports fourth quarter and full year 2025 financial results · Manufacturer · 2026-02-25 — Company describes IMC-S118AI as PPI × PD1 ImmTAAI for T1D and said the Phase 1 trial would begin in the first half of 2026.