# POD1UM-201 (retifanlimab in advanced Merkel cell carcinoma)

Source: https://onco.cc/trials/pod1um-201/  
OnCo record `pod1um-201` (Trial). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

The third PD-1 antibody tested in this rare and fast-growing skin cancer shrank it in more than half of the people who took it, and most of those responses lasted years. Six in ten were still alive three years later, in a disease that used to kill within months.

## Summary

Merkel cell carcinoma is rare, aggressive and unusually visible to the immune system, either because it carries the Merkel cell polyomavirus or because it is driven by ultraviolet damage with a very high mutational burden. POD1UM-201 tested retifanlimab, a humanised PD-1 antibody, in 101 chemotherapy-naive patients with recurrent locally advanced or metastatic disease across 34 sites in the United States, Canada and Europe.

The objective response rate was 54.5 per cent (95 per cent confidence interval 44.2 to 64.4), made up of 18 complete responses (17.8 per cent) and 37 partial responses (36.6 per cent), with a disease control rate of 60.4 per cent. Duration matters more than rate in this disease, because chemotherapy responses had been measured in months: median duration of response was not reached in those with a complete response, with a lower confidence bound of 14.0 months, and was 25.3 months in those with a partial response. Median progression-free survival was 16.0 months (9.0 to 32.2) and median overall survival was not reached, with 63 per cent of patients alive at three years.

Grade 3 immune-related adverse events occurred in 11 patients (10.9 per cent), in keeping with the class.

Retifanlimab became the third PD-1 or PD-L1 antibody approved for this disease after avelumab and pembrolizumab, and the three have never been compared with each other. What matters is not which is chosen but that roughly half of the patients respond and most responders keep responding, which is the single largest change in the history of this cancer.

## Fields

- Kind: Trial
- Status: positive
- Last checked: 2026-09-25
- Also known as: POD1UM-201
- Registry id: NCT03599713
- Phase: 2
- Setting: Recurrent locally advanced or metastatic Merkel cell carcinoma not amenable to surgery or radiotherapy, with no previous systemic treatment: retifanlimab 500 mg intravenously every four weeks for up to two years, with objective response rate as the primary endpoint
- Sponsor: Incyte Corporation
- Enrolled: 101
- Result: Objective response in 54.5 per cent (95 per cent confidence interval 44.2 to 64.4) with complete responses in 17.8 per cent, median progression-free survival 16.0 months, and 63 per cent of patients alive at three years.
- Outcomes: Objective response rate: Retifanlimab 500 mg every 4 weeks 54.5%; Median progression-free survival: Retifanlimab 500 mg every 4 weeks 16 months; Overall survival at 3 years: Retifanlimab 500 mg every 4 weeks 63%; Grade 3 immune-related adverse events: Retifanlimab 500 mg every 4 weeks 10.9%
- Replication: JAVELIN Merkel 200 part B found a first-line response rate of 39.7 per cent with avelumab and KEYNOTE-017 found 56 per cent with pembrolizumab, so all three antibodies sit in the same range; none has been compared with another.

## Sources

- ClinicalTrials.gov NCT03599713: https://clinicaltrials.gov/study/NCT03599713
- Primary report (Journal for ImmunoTherapy of Cancer 2025): https://doi.org/10.1136/jitc-2025-012478
- Primary report on PubMed: https://pubmed.ncbi.nlm.nih.gov/40796223/

## 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: [Retifanlimab](https://onco.cc/drugs/retifanlimab/)
- companies: [Incyte](https://onco.cc/companies/incyte/)
- terms: [Immune-related adverse events (irAEs)](https://onco.cc/terms/irae/), [Merkel cell polyomavirus (MCPyV) status](https://onco.cc/terms/mcpyv-status/), [Tumour mutational burden (TMB)](https://onco.cc/terms/tmb/)
- trials: [ADMEC-O (adjuvant nivolumab in completely resected Merkel cell carcinoma)](https://onco.cc/trials/admec-o/), [JAVELIN Merkel 200](https://onco.cc/trials/javelin-merkel-200/), [KEYNOTE-017 (Cancer Immunotherapy Trials Network 09)](https://onco.cc/trials/keynote-017/), [STAMP (EA6174)](https://onco.cc/trials/stamp-merkel/)

---
JSON: https://onco.cc/api/v1/entities/pod1um-201.json