- Histologically proven diagnosis of Merkel cell carcinoma (MCC).
- Clinical stage I-II MCC (AJCC 8th edition).
- Patients must be considered candidates for wide local surgical excision and sentinel
lymph node biopsy.
- Provision of signed and dated informed consent form
- Stated willingness to comply with all study procedures and availability for the
duration of the study
- Male or female, aged at least 18 years
- ECOG performance Status of 0, 1, or 2
- Adequate baseline laboratory assessments within 28 days of study registration:
1. Adequate hepatic function: i. Total bilirubin ≤1.5 x upper limit of normal (ULN)
(NOTE: For patients with Gilbert's syndrome, total bilirubin ≤3 x ULN) ii.
Transaminases (aspartate aminotransferase [AST] and alanine aminotransferase
[ALT]) ≤3 x ULN iii. Alkaline phosphatase (ALP) ≤2.5 x ULN
2. Adequate renal function: Serum creatinine ≤1.5 x ULN or estimated creatinine
clearance (CrCl) >30 mL/min according to the method of Cockcroft and Gault.
3. Adequate bone marrow function: i. Hemoglobin ≥9.0 g/dL ii. Absolute neutrophil
count (ANC) ≥1.0 x 109/L iii. Platelet count ≥75 x 109/L
- Patients who are HIV+ with undetectable HIV viral load are eligible.
- For females of reproductive potential: use of highly effective contraception for at
least 1 month prior to screening and agreement to use such a method during study
participation and for an additional 6 months after the end of cemiplimab
- For males of reproductive potential: use of condoms or other methods to ensure
effective contraception with partner
- Concurrent malignancy other than localized CSCC and/or history of malignancy other
than Merkel cell carcinoma within 3 years of date of registration on the study, except
for tumors with negligible risk of metastasis or death, such as adequately treated
(BCC) of the skin, carcinoma in situ of the cervix, or ductal carcinoma in situ of the
breast, or low- risk early stage prostate adenocarcinoma (T1-T2aN0M0 and Gleason score
≤6 and prostate-specific antigen (PSA) ≤10 ng/mL) for which the management plan is
active surveillance, or prostate adenocarcinoma with biochemical-only recurrence with
documented PSA doubling time of >12 months for which the management plan is active
- Patients with hematologic malignancies (eg, chronic lymphocytic leukemia [CLL]).
- Ongoing or recent (within 5 years of registration date) evidence of significant
autoimmune disease that required treatment with systemic immunosuppressive treatments,
which may suggest risk for immune-related adverse events (irAEs). Further, patients
requiring chronic immune-suppressive therapy are excluded. The following are not
exclusionary: vitiligo, childhood asthma that has resolved, type 1 diabetes, residual
hypothyroidism that required only hormone replacement, or psoriasis that does not
require systemic treatment.
- Pregnancy or lactation.
- Has participated in a study of an investigational agent or an investigational device
within 4 weeks of the enrollment date.
- Receipt of a live vaccine within 28 days of the registration date.
- Has had prior systemic anti-cancer immunotherapy for MCC. Examples of immune
modulating agents include but are not limited to blockers of CTLA-4, 4-1BB (CD137), or
OX-40, therapeutic vaccines, anti-PD-1/PD-L1.
- Immunosuppressive corticosteroid doses (>10 mg prednisone daily or equivalent) within
4 weeks prior to the first dose of cemiplimab/placebo.
NOTE: Patients who require brief course of corticosteroids (eg, prophylaxis for imaging
assessments due to hypersensitivity to contrast agents) are not excluded. People taking
steroids for physiologic replacement (ie, adrenal insufficiency) are NOT excluded.
- Has received treatment with an approved anticancer systemic therapy within 4 weeks of the
registration date or has not yet recovered (ie, ≤ grade 1 or baseline) from any acute
toxicities except for laboratory changes as described in the inclusion criteria.
NOTE: Patients receiving bisphosphonates or denosumab are not excluded.
- Prior allogeneic stem cell transplantation, or autologous stem cell transplantation.
- Patients who have permanently discontinued anti-cancer immune modulating therapies due
to drug-related toxicity.
- Encephalitis, meningitis, or uncontrolled seizures in the year prior to screening.
- Patients with myocardial infarction within 6 months prior to the registration date.
- Any infection requiring hospitalization and/or intravenous antibiotic therapy within 2
weeks of the registration date.
- Active tuberculosis.
- Uncontrolled infection with human immunodeficiency virus (HIV), hepatitis B or
hepatitis C virus (HBV or HCV) infection; or diagnosis of immunodeficiency.
- Patients with known HIV infection who have controlled infection (undetectable viral
load (HIV RNA PCR) and CD4 count above 350, either spontaneously or on a stable
antiviral regimen) are permitted. For patients with controlled HIV infection,
monitoring will be performed per local standards.
- Patients with HBV (hepatitis B surface antigen positive; HepBsAg+) who have controlled
infection (serum HBV DNA PCR that is below the limit of detection AND receiving anti-
viral therapy for HBV) are permitted. Patients with controlled infections must undergo
periodic monitoring of HBV DNA. Patients must remain on anti-viral therapy for at
least 6 months beyond the last dose of investigational study drug.
Patients who are HCV antibody positive (HCV Ab+) who have controlled infection
(undetectable HCV RNA by PCR, either spontaneously or in response to a successful prior
course of anti-HCV therapy) are permitted.
- History of immune related pneumonitis within the last 5 years.
- History of interstitial lung disease (eg, idiopathic pulmonary fibrosis, organizing
pneumonia) or active, noninfectious pneumonitis that required immune-suppressive doses
of glucocorticoids to assist with management. A history of radiation pneumonitis in
the radiation field is permitted as long as pneumonitis resolved ≥6 months prior to
the registration date.
- History of documented allergic reactions or acute hypersensitivity reaction attributed
to antibody treatments.
- Known hypersensitivity or allergy to any of the excipients in the cemiplimab drug
- Patients with a history of solid organ transplant (exception: patients with prior
corneal transplant are not excluded).
- Any medical co-morbidity, physical examination finding, or metabolic dysfunction, or
clinical laboratory abnormality that, in the opinion of the investigator, renders the
patient unsuitable for participation in a clinical trial due to high safety risks
and/or potential to affect interpretation of results of the study.
- Known psychiatric or substance abuse disorders that would interfere with participation
with the requirements of the study.