title: Metastatic Merkel cell carcinoma response to nivolumab.
abstract: BACKGROUND
  Merkel cell carcinoma (MCC) is an aggressive cutaneous neuroendocrine malignancy with limited treatment options. Several lines of evidence support the programmed death-1/programmed death-ligand 1 (PD-1/PD-L1) axis as a likely contributor to immune evasion in MCC.
  
  
  METHODS
  We report a case of a patient with metastatic MCC with a significant and durable response to nivolumab, a humanized IgG4 monoclonal anti-PD-1 antibody.
  
  
  CONCLUSIONS
  Immunotherapy with PD-1/PD-L1 inhibitors has become a rational and promising treatment option for MCC in the advanced or metastatic disease. Clinical trials are currently in progress to further evaluate these novel therapeutic agents.
authors.affiliation: University of Michigan Medical School, Ann Arbor, MI USA.
authors.forename: Frances M
authors.initials: FM
authors.lastname: Walocko
authors.affiliation: Division of Hematology/Oncology, Department of Internal Medicine, University of Michigan, C451 Med Inn, 1500 East Medical Center Drive, Ann Arbor, MI 48109 USA.
authors.forename: Benjamin Y
authors.initials: BY
authors.lastname: Scheier
authors.affiliation: Department of Pathology, University of Michigan, Ann Arbor, MI USA ; Department of Dermatology, University of Michigan, Ann Arbor, MI USA.
authors.forename: Paul W
authors.initials: PW
authors.lastname: Harms
authors.affiliation: Division of Hematology/Oncology, Department of Internal Medicine, University of Michigan, C451 Med Inn, 1500 East Medical Center Drive, Ann Arbor, MI 48109 USA.
authors.forename: Leslie A
authors.initials: LA
authors.lastname: Fecher
authors.affiliation: Division of Hematology/Oncology, Department of Internal Medicine, University of Michigan, C451 Med Inn, 1500 East Medical Center Drive, Ann Arbor, MI 48109 USA.
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Lao
keywords: Case report; Immunotherapy; Merkel cell carcinoma; Nivolumab; PD-L1; Polyomavirus