Paolo A. Ascierto, MD, National Tumor Institute, Milan, Italy, explains the rationale of the MERKLIN 1 trial (NCT04874831), which investigates the efficacy of a histone deacetylase inhibitor, domatinostat, in combination with a PD-1 inhibitor, avelumab in patients with treatment-naïve metastatic Merkel cell carcinoma (MCC). This interview took place at the European Society for Medical Oncology (ESMO) 2021 congress.