DNER and Thrombocytopenia: Multiple first-in-human studies of BET inhibitors have now been published, with the majority of compounds being analogues of JQ1, the first identified BET inhibitor.3 The chemical composition of ODM-207 is distinct from JQ1 analogues, but notably had overlapping profile of adverse events with other compounds.12,24 Consistently with other BET inhibitors, treatment-related adverse events limited dose escalation with most commonly observed AEs being thrombocytopenia, nausea, fatigue, decreased appetite, and diarrhoea.