# ADU-S100 (MIW815)

Source: https://onco.cc/drugs/adu-s100/  
OnCo record `adu-s100` (Treatment). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

ADU-S100 was the first STING agonist in the clinic. Injected directly into tumours, it produced almost no responses, alone or with checkpoint blockade.

## Summary

A cyclic dinucleotide STING agonist from Aduro (partnered with Novartis). Phase 1 monotherapy and combinations with spartalizumab or ipilimumab produced single-digit response rates; Novartis returned rights in 2019 and Aduro discontinued the programme in 2020. Merck's MK-1454 followed the same path. The pathway remains important (it mediates immune effects of radiation and ADCs), and systemic and antibody-conjugated STING agonists continue.

Lesson: intratumoural delivery to one lesion rarely produces systemic immunity in humans as it does in mice; pharmacology (rapid clearance, dosing) matters as much as the target.

## Fields

- Kind: Treatment
- Status: withdrawn
- Last checked: 2026-09-06
- Tags: failure; lesson:wrong-drug
- Code: ADU-S100
- Modality: Small molecule (STING agonist, intratumoural)
- Mechanism: Synthetic cyclic dinucleotide activating STING → TBK1 → IRF3 → type I interferon.

## Sources

- ADU-S100 phase 1 (Cancer Discov 2023): https://aacrjournals.org/cancerdiscovery/article/13/5/1117/725648

## Connected records

- cancers: [Head and neck squamous cell carcinoma](https://onco.cc/cancers/head-and-neck/), [Melanoma](https://onco.cc/cancers/melanoma/)
- technologies: [STING & innate immune agonists](https://onco.cc/technologies/sting-agonist/)
- companies: [Novartis](https://onco.cc/companies/novartis/)
- pathways: [cGAS-STING innate sensing](https://onco.cc/pathways/cgas-sting/), [Cold tumours: immune deserts and exclusion](https://onco.cc/pathways/immune-desert-exclusion/)
- trials: [Efficacy and Safety Trial of ADU-S100 and Pembrolizumab in Head and Neck Cancer](https://onco.cc/trials/nct03937141/)
- bottlenecks: [Cold tumours and the immunosuppressive microenvironment](https://onco.cc/bottlenecks/b-tme-immunosuppression/)
- targets: [TBK1](https://onco.cc/targets/tbk1/)

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