This is a single-arm (group), open-label (all people know the identity of the intervention), and multicenter study. The study consists of 3 phases including, the screening phase (within 28 days prior to the start of study medication), treatment phase (participants will receive quisinostat) and follow-up phase (30 days after the last dose of study medication until death or clinical cutoff). Clinical cut-off is defined as when the last participant will be assessed with progressive disease or died, or 6 months after the last participant enrolled, whichever occurs first. However, if any participants are still receiving study treatment at the time of clinical cut-off, these participants will enter a long-term extension phase and will continue to receive study medication until a reason for discontinuation is met (ie, disease progression, toxicity, availability of other effective medications that the participant may receive, or treating physician advice). The long-term extension phase will continue for a maximum of 2 years beyond the clinical cut-off for primary analysis. Safety will be evaluated by the assessment of adverse events, vital signs, physical examination, 12-lead electrocardiogram, and clinical laboratory tests which will be monitored in this study. Any participants responding to treatment at the end of the 2-year long-term extension phase will be able to continue to receive quisinostat as long as they are assessed by the investigator as not meeting treatment discontinuation criteria; during this time, only information related to serious adverse events will be collected.
