# Favezelimab

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

## TL;DR

Favezelimab is Merck's LAG-3 antibody, tested with pembrolizumab in phase 3 trials in colorectal cancer and classical Hodgkin lymphoma; the colorectal trial did not succeed.

## Summary

Merck's favezelimab (MK-4280) blocks LAG-3, the second checkpoint validated by relatlimab in melanoma. Coformulated with pembrolizumab as MK-4280A, it entered phase 3 trials in previously treated microsatellite-stable colorectal cancer, where the trial did not meet its overall survival endpoint, and in relapsed classical Hodgkin lymphoma after PD-1 therapy. Registered phase 3 trials remain on ClinicalTrials.gov.

## Fields

- Kind: Treatment
- Status: phase-3
- Last checked: 2026-09-16
- Tags: pipeline; ctgov-ingest
- Code: MK-4280
- Modality: Anti-LAG-3 monoclonal antibody, intravenous, also coformulated with pembrolizumab (MK-4280A)
- Mechanism: Blocks the LAG-3 checkpoint on exhausted T cells; given with PD-1 blockade to overcome resistance to pembrolizumab alone.

## Sources

- ClinicalTrials.gov: trials of Favezelimab: https://clinicaltrials.gov/search?intr=MK-4280

## Connected records

- cancers: [Colorectal cancer](https://onco.cc/cancers/colorectal/), [Hodgkin lymphoma](https://onco.cc/cancers/hodgkin-lymphoma/)
- technologies: [Immune checkpoint inhibitors](https://onco.cc/technologies/checkpoint-inhibitor/), [LAG-3 blockade](https://onco.cc/technologies/lag3-blockade/)
- targets: [LAG-3](https://onco.cc/targets/lag3/)
- trials: [A Study of Efficacy and Safety of Pembrolizumab Plus Enfortumab Vedotin (EV) +/- Investigational Agents in First-Line Metastatic Urothelial Carcinoma (mUC) (MK-3475-04B/KEYMAKER-U04)](https://onco.cc/trials/nct05845814/), [Evaluation of Co-formulated Pembrolizumab/Quavonlimab (MK-1308A) Versus Other Treatments in Participants With Microsatellite Instability-High (MSI-H) ](https://onco.cc/trials/nct04895722/), [Long-term Safety and Efficacy Extension Study for Participants With Advanced Tumors Who Are Currently on Treatment or in Follow-up in a Pemb](https://onco.cc/trials/nct03486873/), [Safety and Efficacy Study of Investigational Agents as Monotherapy or in Combination With Pembrolizumab (MK-3475) for the Treatment of Extensive-Stage Small Cell Lung Cancer (ES-SCLC) in Need of Second-Line Therapy (MK-3475-B98/KEYNOTE-B98)](https://onco.cc/trials/nct04938817/), [Substudy 03A: A Study of Immune and Targeted Combination Therapies in Participants With First Line (1L) Renal Cell Carcinoma (MK-3475-03A)](https://onco.cc/trials/nct04626479/), [Substudy 03B: A Study of Immune and Targeted Combination Therapies in Participants With Second Line Plus (2L+) Renal Cell Carcinoma (MK-3475-03B/KEYMAKER-U03)](https://onco.cc/trials/nct04626518/)

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