Disease Control Rate (DCR), defined as the proportion of patients with either an objective response (CR, PR) or stable disease (SD) according to RECIST v1.1.

Durable Disease Control Rate (dDCR), defined as the percentage of patients having a RECIST v1.1 disease control lasting ≥ 6 months

Best Overall response (BOR), defined as the best response (PD, SD, PR, CR) according to RECIST v1.1 over the course of a patient's participation in the study, assessed up to 2 years

Progression Free Survival (PFS), defined as the time from first dosing (Day +1) to the date of PD or death from any cause (whichever comes first)

PFS Rate, defined as the percentage of patients without PD at 6 and 12 months after first administration of study drug

Overall Survival (OS), defined as the time from the first administration of study medication until death due to any cause

OS Rate, defined as the percentage of patients alive at 6 and at 12 months after first administration of study drug

Safety and Tolerability of the study medication (determined by number, frequency, duration and severity of AEs using CTCAE v5.0, physical examination, laboratory tests, vital signs, and ECGs)

The impact of treatment on the patient's QoLwill be assessed with the questionnaires "Functional Assessment of Cancer Therapy - Melanoma (FACT-M)" where QoL is assessed on a scale 0-240 (higher score means better status of health), with "EQ-5D-5L" which is a multi attribute utility instrument for measuring health-related QoL as EQ5D index with a score 0-1 (higher score means better status of health) and with the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC-QLQ-C30) with a score 0-100 per subscale (n=9 per item (n=6), higher score means better QoL.

Single trough values of domatinostat and avelumab at pre-defined time points

Avelumab anti-drug antibodies (ADA)