[Immune checkpoint inhibition in Merkel cell carcinoma]

Area of Science:

• Oncology
• Dermatology
• Immunology

Background:

• Merkel cell carcinoma (MCC) is a rare, aggressive skin cancer.
• Key risk factors include Merkel cell polyomavirus infection and UV exposure.
• Immune checkpoint inhibitors have transformed MCC treatment.

Purpose of the Study:

• To review modern MCC management strategies.
• Focus on MCC tumor biology and immune checkpoint inhibitors (PD-1/PD-L1).

Main Methods:

• Systematic review of scientific literature.
• PubMed database search.

Main Results:

• First-line avelumab (PD-L1 inhibitor) shows a 62% response rate.
• Second-line therapy yields a 33% response rate, with 69% relapse-free at 2 years.
• Pembrolizumab (anti-PD-1) offers a 69% 2-year survival rate; chemotherapy response is transient.

Conclusions:

• Checkpoint inhibition is an effective MCC treatment.
• Avelumab is approved for metastatic MCC; chemotherapy is an alternative for resistance/contraindications.
• Adjuvant/neoadjuvant checkpoint inhibition is a potential future strategy.