Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Case Reports
. 2025 Jun;17(8):561-566.
doi: 10.1080/1750743X.2025.2517522. Epub 2025 Jun 13.

Pembrolizumab-induced myocarditis, myositis, and myasthenia gravis overlap syndrome (IM3OS) treated with Efgartigimod: case report

Stephanie S Cobelas-Cartagena  1 , Emilio Amigo-Otero  2 , Victoria García-Samblas  1 , Jesus Flores-Raposo  1 , Silvia Rodrigo-Herrero  3 , Juan Bayo-Calero  1
Affiliations
Case Reports

Pembrolizumab-induced myocarditis, myositis, and myasthenia gravis overlap syndrome (IM3OS) treated with Efgartigimod: case report

Stephanie S Cobelas-Cartagena et al. Immunotherapy. 2025 Jun.

Abstract

The use of immune checkpoint inhibitors (ICIs) has revolutionized the treatment of many malignancies. However, they may be associated with life-threatening immune-mediated adverse effects.In this article, we present the case of a patient diagnosed with stage IIB acral melanoma (pT4aN0M0) who started adjuvant treatment with pembrolizumab, after which he developed severe myocarditis with myositis and myasthenia gravis overlap syndrome (IM3OS) treated with Efgartigimod.The use of Efgartigimod resulted in a remarkable recovery, marking the first reported acute application of this agent for IM3OS and positive anti-acetylcholine receptor antibodies (anti-AChR).

Keywords: Efgartigimod; Immune checkpoint inhibitors; case report; immune-related adverse events; myocarditis, myositis and myasthenia gravis overlap syndrome (IM3OS).

PubMed Disclaimer

Conflict of interest statement

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

No writing assistance was utilized in the production of this manuscript.

References

    1. Carlino MS, Larkin J, Long GV.. Immune checkpoint inhibitors in melanoma. The Lancet. 2021;398(10304):1002–1014. doi: 10.1016/S0140-6736(21)01206-X - DOI - PubMed
    1. Cooper AJ, Carlino MS, Kefford RF. Immune checkpoint inhibitors in melanoma. Melanoma Manag. 2015;2(3):267–284. doi: 10.2217/mmt.15.17 - DOI - PMC - PubMed
    1. Postow MA, Sidlow R, Hellmann MD, et al. Immune-related adverse events associated with immune checkpoint blockade. N Engl J Med. 2018;378(2):158–168. doi: 10.1056/NEJMra1703481 - DOI - PubMed
    1. Yousif LI, Screever EM, Versluis D, et al. Risk factors for immune checkpoint inhibitor–mediated cardiovascular toxicities. Curr Oncol Rep. 2023;25(7):753–763. doi: 10.1007/s11912-023-01414-4 - DOI - PMC - PubMed
    1. Martins F, Sofiya L, Sykiotis GP, et al. Adverse effects of immune-checkpoint inhibitors: epidemiology, management and surveillance. Nat Rev Clin Oncol. 2019;16(9):563–580. doi: 10.1038/s41571-019-0218-0 - DOI - PubMed

Publication types

MeSH terms

Substances

LinkOut - more resources