Response to pembrolizumab in a patient with xeroderma pigmentosum, metastatic cutaneous melanoma and multiple squamous cell carcinomas: a case report.

Xeroderma pigmentosum (XP) is a rare genetic disorder associated with defective DNA repair, leading to extreme ultraviolet sensitivity and a significantly elevated risk of malignancies. This case report details a patient with XP and metastatic melanoma who achieved complete clinical remission with pembrolizumab, highlighting the potential efficacy of immune checkpoint inhibitors in tumours with high mutational burdens. These findings underscore a promising therapeutic avenue for this vulnerable population with limited treatment options.