Pembrolizumab With or Without Stereotactic Body Radiation Therapy in Treating Patients With Advanced or Metastatic Merkel Cell Cancer


About this study

This randomized phase II trial studies how well pembrolizumab with or without stereotactic body radiation therapy works in treating patients with merkel cell cancer that has spread to other places in the body. Monoclonal antibodies, such as pembrolizumab, may interfere with the ability of tumor cells to grow and spread. Stereotactic body radiation therapy is a specialized radiation therapy that sends x-rays directly to the tumor using smaller doses over several days and may cause less damage to normal tissue. Giving pembrolizumab with stereotactic body radiation therapy may work better in treating patients with merkel cell cancer.

Participation eligibility

Participant eligibility includes age, gender, type and stage of disease, and previous treatments or health concerns. Guidelines differ from study to study, and identify who can or cannot participate. There is no guarantee that every individual who qualifies and wants to participate in a trial will be enrolled. Contact the study team to discuss study eligibility and potential participation.

Inclusion Criteria:

  • Patients must have pathologically (histologically or cytologically) proven diagnosis of MCC by local pathology review
  • Have measurable disease based on RECIST 1.1 including at least two cancerous deposits; at least one deposit must be RECIST measurable while at least one deposit must meet criteria for SBRT; non-radiated tumor will be identified prior to randomization on the protocol
  • Patients must have advanced or metastatic MCC defined as evidence of distant metastasis(es) on imaging
    • Patients with locoregionally confined disease are not eligible
  • No prior immunotherapy for advanced/metastatic MCC
  • Patients with known or suspected central nervous system (CNS) metastases, untreated CNS metastases, or with the CNS as the only site of disease are excluded; however, subjects with controlled brain metastases will be allowed to enroll; controlled brain metastases are defined as no radiographic progression for at least 4 weeks following radiation and/or surgical treatment (or 4 weeks of observation if no intervention is clinically indicated), and off of steroids for at least 2 weeks, and no new or progressive neurological signs and symptoms
  • Patients having received palliative radiotherapy for extracranial metastasis(es) are eligible as long as there are 2 cancerous deposits that have not received prior radiation therapy (RT) and they meet the following criteria
    • No prior radiation therapy (> 5 Gy) to the metastasis intended to be treated with SBRT
  • No history of the following:
    • Autoimmunity requiring systemic immunosuppression within 2 years
    • Patients known to be human immunodeficiency virus (HIV) positive are eligible if they meet the following:
      • CD4 counts >= 350 mm^3
      • Serum HIV viral load of < 25,000 IU/ml
  • No other active malignancy that the investigator determines would interfere with the treatment and safety analysis
  • Not pregnant and not nursing; therefore, for women of childbearing potential only, a negative (if your test schedule specifically indicates a urine or serum pregnancy test, add that information at this point) pregnancy test done =< 28 days prior to registration is required
  • Eastern Cooperative Oncology Group (ECOG) performance status 0-2
  • Absolute neutrophil count (ANC) >= 1,500/mm^3
  • Platelet count >= 100,000/mm^3
  • Hemoglobin >= 9.0 g/dl
  • Total bilirubin =< 2.0 mg/dl
  • Aspartate aminotransferase (AST)/alanine aminotransferase (ALT) =< 3.0 x upper limit of normal (ULN)
  • Systolic blood pressure (BP) =< 150 mg HG
  • Diastolic BP =< 90 mg HG
  • Albumin > 3 mg/dl
  • Blood urea nitrogen (BUN) =< 30 mg/dl
  • Creatinine =< 1.7 mg/dl
  • The following imaging workup to document metastases within 45 days prior to study registration are required: CT scans of the chest, abdomen and pelvis with radionuclide bone scan OR whole body (at least skullbase to midthigh) positron emission tomography (PET)/CT

Participating Mayo Clinic locations

Study statuses change often. Please contact the study team for the most up-to-date information regarding possible participation.

Mayo Clinic Location Status Contact

Rochester, Minn.

Mayo Clinic principal investigator

Katharine Price, M.D.

Closed for enrollment

Contact information:

Cancer Center Clinical Trials Referral Office


More information


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