STAMP: Surgically Treated Adjuvant Merkel Cell Carcinoma With Pembrolizumab, a Phase III Trial

Plain English Summary

Testing Pembrolizumab Versus Observation in Patients With Merkel Cell Carcinoma After Surgery, STAMP Trial is a Phase 3 clinical trial sponsored by National Cancer Institute (NCI) studying Pathologic Stage I Cutaneous Merkel Cell Carcinoma AJCC v8, Pathologic Stage II Cutaneous Merkel Cell Carcinoma AJCC v8, Pathologic Stage III Cutaneous Merkel Cell Carcinoma AJCC v8. This trial compares pembrolizumab to observation after surgery for Merkel cell carcinoma. Eligible patients are those with stages I-III Merkel cell carcinoma who have had surgery to remove the cancer. Participants will receive pembrolizumab or observation, and will be monitored for recurrence and survival. Alternatives include standard observation without additional treatment. The trial aims to enroll 280 participants.

Official Summary

This phase III trial studies how well pembrolizumab works compared to standard of care observation in treating patients with stage I-III Merkel cell cancer that has been completely removed by surgery (resected). Immunotherapy with monoclonal antibodies, such as pembrolizumab, may help the body's immune system attack the cancer, and may interfere with the ability of tumor cells to grow and spread.

Who Can Participate

Here is what you need to know about eligibility for this trial. Eligible: 18 years or older, no pregnancy, no history of distant metastatic disease, no active immunosuppression. Not eligible: Pregnant, breastfeeding, history of distant metastatic disease, active immunosuppression, certain liver or kidney issues. This trial is studying Pathologic Stage I Cutaneous Merkel Cell Carcinoma AJCC v8, Pathologic Stage II Cutaneous Merkel Cell Carcinoma AJCC v8, Pathologic Stage III Cutaneous Merkel Cell Carcinoma AJCC v8, so participants generally need a confirmed diagnosis.

What They're Measuring

The primary outcome measures recurrence-free survival and overall survival, which are crucial for patients in understanding their chances of long-term survival. The specific primary outcome measures are: Recurrence free survival (RFS) (From randomization until disease recurrence or death from any cause; assessed up to 5 years); OS (From randomization until death, assessed up to 5 years). These endpoints are how researchers determine whether the treatment is effective and will form the basis of any future regulatory submissions.

About This Phase

This trial is in Phase 3, the final and most rigorous stage before seeking FDA approval. Phase 3 trials involve 300-3,000+ patients across multiple sites and compare the new treatment directly against the current standard of care. These pivotal trials generate the evidence needed for regulatory review. About 58% of Phase 3 drugs receive FDA approval. Successful Phase 3 results typically lead to a New Drug Application submission.

Why This Trial Matters

This trial addresses a treatment gap by evaluating the effectiveness of immunotherapy in Merkel cell carcinoma, a rare and aggressive skin cancer. As a Phase 3 trial, positive results could directly lead to FDA approval, making this treatment available to the broader patient population. This research targets Pathologic Stage I Cutaneous Merkel Cell Carcinoma AJCC v8, Pathologic Stage II Cutaneous Merkel Cell Carcinoma AJCC v8, Pathologic Stage III Cutaneous Merkel Cell Carcinoma AJCC v8, where improved treatment options are needed.

Investor Insight

The market size for Merkel cell carcinoma treatments is growing, with limited approved options, making this trial significant for investors. Phase 3 trials have approximately a 50-60% chance of gaining FDA approval if they reach this stage.

Is This Trial Right for Me?

Ask your doctor if you have had surgery to remove Merkel cell carcinoma and are in stages I-III. Understand that you will be randomly assigned to receive either pembrolizumab or observation. The trial is being conducted at 20 sites. Always discuss clinical trial participation with your healthcare provider before making any decisions. This information is for educational purposes only and is not medical advice.

AI-generated analysis for educational purposes only. This is not medical advice. Discuss clinical trial participation with your doctor. Data sourced from ClinicalTrials.gov.

Study Design

• Study Type: INTERVENTIONAL
• Allocation: RANDOMIZED
• Model: PARALLEL
• Masking: NONE
• Enrollment: 280 participants

Interventions

• OTHER: Best Practice — Receive standard of care observation
• PROCEDURE: Biospecimen Collection — Undergo blood and urine sample collection
• PROCEDURE: Computed Tomography — Undergo PET-CT or CT
• PROCEDURE: Magnetic Resonance Imaging — Undergo MRI
• BIOLOGICAL: Pembrolizumab — Given IV

Primary Outcomes

• Recurrence free survival (RFS) (From randomization until disease recurrence or death from any cause; assessed up to 5 years)
• OS (From randomization until death, assessed up to 5 years)

Secondary Outcomes

• Impact of radiation therapy on RFS (Up to 5 years)
• Impact of radiation therapy on OS (Up to 5 years)
• Impact of radiation therapy on distant metastasis free survival (DMFS) (From randomization to distant metastasis, assessed up to 5 years)
• Incidence of adverse events (Up to 5 years)

Full Eligibility Criteria

Inclusion Criteria:

* Patient must be \>= 18 years of age
* Patients must have an Eastern Cooperative Oncology Group (ECOG) performance status: 0, 1, or 2 (However, those patients with a performance state of 3 because they are wheel chair bound due to congenital or traumatic events more than one year before the diagnosis of Merkel cell carcinoma are eligible).
* Patient must not be pregnant or breast-feeding due to the unknown effects of the study drug in this setting. All patients of childbearing potential must have a blood test or urine study within 2 weeks prior to randomization to rule out pregnancy. A patient of childbearing potential is anyone, regardless of sexual orientation or whether they have undergone tubal ligation, who meets the following criteria: 1) has achieved menarche at some point, 2) has not undergone a hysterectomy or bilateral oophorectomy; or 3) has not been naturally postmenopausal (amenorrhea following cancer therapy does not rule out childbearing potential) for at least 24 consecutive months (i.e., has had menses at any time in the preceding 24 consecutive months).
* Patients on Arm A pembrolizumab (MK-3475) must not conceive or father children by using accepted and effective method(s) of contraception or by abstaining from sexual intercourse from the time of registration, while on study treatment, and continue for 120 days after the last dose of study treatment. For patients on Arm B only receiving radiation therapy, contraception use should be per institutional standard.
* Patient must have a histological confirmation of diagnosis of Merkel cell carcinoma (MCC), pathologic stages (American Joint Committee on Cancer \[AJCC\] version 8) I-IIIb.

  * Stage I patients with negative sentinel lymph node biopsy are ineligible. Patients who have a positive biopsy or for whom no biopsy was done are eligible.
  * Patients with distant metastatic disease (stage IV) are ineligible.
  * The primary tumor must have grossly negative margins. (Microscopically positive margins are allowed).
  * Cancers of unknown primary that have regional disease only are eligible.
  * Complete nodal dissection is not required for eligibility.
* Patients with all macroscopic Merkel cell carcinoma (either identified by physical exam or imaging) must have been completely resected by surgery within 16 weeks before randomization.
* All patients must have disease-free status documented by a complete physical examination and conventional imaging studies within 8 weeks prior to randomization.
* Patient may not have a history of distant metastatic disease.

  * NOTE: Loco-regional recurrent disease is acceptable, as long as this is not metastatic (prior surgery with or without radiation therapy is acceptable).
* For patients with initial presentation of Merkel cell carcinoma, patient must have no previous systemic therapy or radiation therapy prior to surgery for Merkel cell carcinoma and cannot have completed adjuvant radiation therapy for Merkel cell carcinoma more than 6 weeks prior to randomization. Patients actively undergoing radiation therapy or having completed adjuvant radiation therapy within 6 weeks of randomization are eligible, as long as resection date is within 16 weeks of randomization. Patients with prior radiation at a non-Radiation Oncology Core (IROC) provider are eligible for the trial. If the patient has not received radiation, and treatment at a Radiation Oncology Core (IROC) provider is not possible, the patient can start and complete radiation prior to randomization, with recommendations to follow radiation protocol guidelines with submission of treatment records.
* White blood count \>= 2000/uL (within 4 weeks prior to randomization).
* Absolute neutrophil count (ANC) \>= 1000/uL (within 4 weeks prior to randomization).
* Platelets \>= 75 x 10\^3/uL (within 4 weeks prior to randomization).
* Hemoglobin \>= 8 g/dL (\>= 80 g/L; may be transfused) (within 4 weeks prior to randomization).
* Creatinine =\< 2.0 x institutional upper limit of normal (ULN) (within 4 weeks prior to randomization).
* Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) =\< 2.5 x institutional ULN (within 4 weeks prior to randomization).
* Total bilirubin =\< 2.0 x institutional ULN, (except patients with Gilbert's syndrome, who must have a total bilirubin less than 3.0 mg/dL) (within 4 weeks prior to randomization).
* Patients who are human immunodeficiency virus (HIV)+ with undetectable HIV viral load are eligible provided they meet all other protocol criteria for participation.
* Patients with hepatitis B virus (HBV) or hepatitis C virus (HCV) infection are eligible provided viral loads are undetectable. Patients on suppressive therapy are eligible.
* Patients must not be on active immunosuppression, have a history of life threatening virus, have had other (beside non-melanoma skin cancers, or recent indolent cancers e.g.: resected low grade prostate cancer) invasive cancer diagnoses in the last two ye

Trial Locations

• University of Alabama at Birmingham Cancer Center, Birmingham, Alabama, United States
• Anchorage Associates in Radiation Medicine, Anchorage, Alaska, United States
• Anchorage Radiation Therapy Center, Anchorage, Alaska, United States
• Alaska Breast Care and Surgery LLC, Anchorage, Alaska, United States
• Alaska Oncology and Hematology LLC, Anchorage, Alaska, United States
• Alaska Women's Cancer Care, Anchorage, Alaska, United States
• Anchorage Oncology Centre, Anchorage, Alaska, United States
• Katmai Oncology Group, Anchorage, Alaska, United States
• Providence Alaska Medical Center, Anchorage, Alaska, United States
• Fairbanks Memorial Hospital, Fairbanks, Alaska, United States
• ...and 10 more locations

Frequently Asked Questions

Related Conditions

• Merkel cell carcinoma, cutaneous squamous cell carcinoma, cutaneous T-cell lymphoma, skin cancer, oncology

More Pathologic Stage I Cutaneous Merkel Cell Carcinoma AJCC v8 Trials

View all Pathologic Stage I Cutaneous Merkel Cell Carcinoma AJCC v8 clinical trials