# ADMEC-O (adjuvant nivolumab in completely resected Merkel cell carcinoma)

Source: https://onco.cc/trials/admec-o/  
OnCo record `admec-o` (Trial). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Merkel cell carcinoma comes back in a quarter of people even after the surgeon has removed it all. Giving immunotherapy afterwards for a year reduced that by about ten in every hundred, but the trial was small and cannot yet say whether anyone lived longer.

## Summary

Merkel cell carcinoma relapses often after complete resection and radiotherapy, and until this trial there was no systemic standard for the situation. Twenty academic centres in Germany and the Netherlands randomised 179 patients 2 to 1 to nivolumab 480 mg every four weeks for a year or to observation. Sixty-five per cent had stage 3 or 4 disease, 68 per cent were 65 or older, and adjuvant radiotherapy was more common in the control group, which is an imbalance worth holding in mind.

At a median follow-up of 24.3 months, median disease-free survival had not been reached in either arm. Disease-free survival was 85 per cent at 12 months and 84 per cent at 24 months with nivolumab, against 77 and 73 per cent with observation, a hazard ratio of 0.58 (95 per cent confidence interval 0.30 to 1.12) whose interval crosses one. The authors state the effect as an absolute risk reduction of 9 percentage points at one year and 10 at two.

Safety is the other half of the trade: grade 3 or 4 adverse events in 48 of 115 treated patients (42 per cent) against 7 of 61 (11 per cent) under observation, with no treatment-related deaths.

The trial's own interpretation is unusually candid and should be quoted rather than smoothed: overall survival had ten events in the treatment group and six in the observation group, which is half the size, and is not mature enough to draw conclusions from. An accompanying comment in the same issue of the journal asked directly whether adjuvant nivolumab should be used on this evidence. It is a phase 2 result in a rare disease, which is often all a rare disease gets, and the honest description is a promising signal rather than a proven standard.

## Fields

- Kind: Trial
- Status: mixed
- Last checked: 2026-09-25
- Also known as: ADMEC-O; ADMEC
- Registry id: NCT02196961
- Phase: 2
- Setting: Completely resected Merkel cell carcinoma of any stage: nivolumab 480 mg every four weeks for one year against observation, randomised 2 to 1 and stratified by stage, age and sex, with landmark disease-free survival at 12 and 24 months as the primary endpoint
- Sponsor: University Hospital Essen, funded by Bristol Myers Squibb
- Enrolled: 179
- Result: Disease-free survival 85 per cent at 12 months and 84 per cent at 24 months with adjuvant nivolumab against 77 and 73 per cent with observation (hazard ratio 0.58, 95 per cent confidence interval 0.30 to 1.12); grade 3 or 4 adverse events 42 against 11 per cent.
- Outcomes: Disease-free survival at 24 months: Adjuvant nivolumab for 1 year 84% vs Observation 73%, HR 0.58; Disease-free survival at 12 months: Adjuvant nivolumab for 1 year 85% vs Observation 77%; Grade 3 or 4 adverse events: Adjuvant nivolumab for 1 year 42% vs Observation 11%
- Replication: STAMP, the ECOG-ACRIN phase 3 of adjuvant pembrolizumab against observation, is the randomised phase 3 test of the same question and has not reported.

## Sources

- ClinicalTrials.gov NCT02196961: https://clinicaltrials.gov/study/NCT02196961
- Interim analysis (The Lancet 2023): https://doi.org/10.1016/S0140-6736(23)00769-9
- Interim analysis on PubMed: https://pubmed.ncbi.nlm.nih.gov/37451295/
- Accompanying comment (The Lancet 2023): https://doi.org/10.1016/S0140-6736(23)01041-3

## Connected records

- cancers: [Merkel cell carcinoma](https://onco.cc/cancers/merkel-cell-carcinoma/), [Skin cancer (all types)](https://onco.cc/cancers/skin-cancer/)
- technologies: [Immune checkpoint inhibitors](https://onco.cc/technologies/checkpoint-inhibitor/)
- targets: [PD-1](https://onco.cc/targets/pd1/)
- drugs: [Nivolumab](https://onco.cc/drugs/nivolumab/)
- companies: [Bristol Myers Squibb](https://onco.cc/companies/bms/)
- terms: [Immune-related adverse events (irAEs)](https://onco.cc/terms/irae/), [Merkel cell polyomavirus (MCPyV) status](https://onco.cc/terms/mcpyv-status/)
- trials: [JAVELIN Merkel 200](https://onco.cc/trials/javelin-merkel-200/), [KEYNOTE-017 (Cancer Immunotherapy Trials Network 09)](https://onco.cc/trials/keynote-017/), [POD1UM-201 (retifanlimab in advanced Merkel cell carcinoma)](https://onco.cc/trials/pod1um-201/), [STAMP (EA6174)](https://onco.cc/trials/stamp-merkel/)

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