Pembrolizumab and Hypofractionated Radiation Therapy for the Treatment of Mucosal Melanoma

The film gives the main points. The full list below is copied from the registry; the study team makes the final decision.

• Age16 Years to no maximum
• SexAll
• Healthy volunteersNo

You may be able to join if

• Histologically or cytologically confirmed mucosal melanoma that has undergone surgical resection. Patient must not have received prior radiation therapy within the area of interest.
• At least 16 years of age.
• Eastern Cooperative Oncology Group (ECOG) performance status ≤ 2 (Karnofsky ≥ 70%)
• Normal bone marrow and organ function as defined below:
• Absolute neutrophil count ≥ 1,200/mcL
• Platelets ≥ 100,000/mcL
• Total bilirubin ≤ 1.5 x institutional upper limit of normal (IULN)
• AST(SGOT)/ALT(SGPT) ≤ 3.0 x IULN
• Creatinine clearance > 30 mL/min by Cockcroft-Gault
• The effects of pembrolizumab on the developing human fetus are unknown. For this reason, women of childbearing potential and men must agree to use adequate contraception (hormonal or barrier method of birth control, abstinence) prior to study entry, for the duration of study participation, and 6 months after last dose of pembrolizumab. Should a woman become pregnant or suspect she is pregnant while participating in this study, she must inform her treating physician immediately. Men treated or enrolled on this protocol must also agree to use adequate contraception prior to the study, for the duration of the study, and 6 months after last dose of pembrolizumab.
• Ability to understand and willingness to sign an IRB approved written informed consent document (or that of legally authorized representative, if applicable).

You cannot join if

• A history of other malignancy with the exception of malignancies for which all treatment was completed at least 2 years before registration and the patient has no evidence of disease.
• Received radiation therapy within the area of interest.
• Currently receiving any other investigational agents.
• Metastatic disease.
• A history of allergic reactions attributed to compounds of similar chemical or biologic composition to pembrolizumab or other agents used in the study.
• Uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, or cardiac arrhythmia.
• Has a diagnosis of immunodeficiency or is receiving systemic steroid therapy or any other form of immunosuppressive therapy within 7 days prior to the first dose of study treatment. The use of up to 10 mg/day of prednisone or equivalent is approved and does not exclude the patient from the trial.
• Active autoimmune disease that has required systemic treatment in past 2 years (i.e., with use of disease modifying agents, > 10 mg of prednisone per day, or immunosuppressive drugs). Replacement therapy (e.g., thyroxine, insulin, or physiologic corticosteroid replacement therapy for adrenal or pituitary insufficiency, etc.) is not considered a form of systemic treatment. The use of up to 10 mg/day of prednisone or equivalent is approved and does not exclude the patient from the trial.
• Has a history of (non-infectious) pneumonitis/Interstitial lung disease that required maintenance steroids (>10 mg of prednisone) or current pneumonitis/interstitial lung disease.
• Has received a live vaccine or live-attenuated vaccination within 30 days of planned treatment start. Administration of killed vaccines is allowed.
• Pregnant and/or breastfeeding. Women of childbearing potential must have a negative pregnancy test within 14 days of study entry.
• Patients with HIV are eligible unless their CD4+ T-cell counts are < 350 cells/mcL or they have a history of AIDS-defining opportunistic infection within the 12 months prior to registration. Concurrent treatment with effective ART according to DHHS treatment guidelines is recommended.

This is how the treatment is meant to work. Whether it helps, and how safe it is, is what this trial is testing.

pembrolizumab. A humanized monoclonal immunoglobulin (Ig) G4 antibody directed against human cell surface receptor PD-1 (programmed death-1 or programmed cell death-1) with potential immune checkpoint inhibitory and antineoplastic activities. Upon administration, pembrolizumab binds to PD-1, an inhibitory signaling receptor expressed on the surface of activated T cells, and blocks the binding to and activation of PD-1 by its ligands, which results in the activation of T-cell-mediated immune responses against tumor cells. The ligands for PD-1 include programmed cell death ligand 1 (PD-L1), overexpressed on certain cancer cells, and programmed cell death ligand 2 (PD-L2), which is primarily expressed on APCs. Activated PD-1 negatively regulates T-cell activation and plays a key role in in tumor evasion from host immunity. NCI Drug Dictionary

Treatments listed in the registry

• Pembrolizumab (Drug): Pembrolizumab is commercially available
• Hypofractionated radiation therapy (Radiation): It is preferred to leave at least 48 hours between fractions. Daily imaging to verify accurate set-up is mandatory.

Na · Single Group · masking: None

As the registry describes them. Requirements to join, such as a tissue sample, are in the eligibility list above even when on-study procedures are optional. Ask the study team which steps apply to you.

• surgery: Part of the study plan
• radiation: Part of the study plan

Main goals

• Local tumor control rate (1 year after completion of treatment (estimated to be 2 years))

Other goals

• Number of treatment-related grade 3 or greater adverse events
• Number of treatment discontinuations due to treatment-related adverse events
• Relapse-free survival (RFS)
• Distant metastasis-free survival
• Overall survival

Planned enrollment: 20 (estimated).

• Washington University School of Medicine, St Louis, Missouri

Site status as of Oct 30, 2026. Check the live record before contacting a site.

• ClinicalTrials.gov NCT04318717
• NCI Drug Dictionary: C106432

Registry record reviewed as fetched Oct 30, 2026, last updated by the sponsor Aug 26, 2026. Public record; not medical advice.