The purpose of this study is to determine whether Resminostat (4SC-201) is effective and safe in the treatment of relapsed or refractory Hodgkin's Lymphoma.

Main Inclusion Criteria:

• Patients must have histological or cytological evidence of Hodgkin's Lymphoma (all subtypes are acceptable)
• Patients must have relapsed or refractory Hodgkin's Lymphoma (HL) defined as relapse following initial therapy or lack of response to first line therapy and treatment with second-line (salvage therapy). Patients may have also undergone high-dose chemotherapy with autologous stem cell transplantation at least 12 weeks prior to study entry
• Patients must have measurable anatomical disease present on CT scan
• Patients must have an ECOG Performance Score of 0, 1 or 2

Main Exclusion Criteria:

• Patients who have received previous treatment with an HDAC inhibitor
• Patients who have undergone allogeneic hematopoietic stem cell transplantation
• Patients with known or suspected involvement of the CNS by HL
• Patients treated with agents known to prolong the QT interval or with a confirmed QTcF > 450 msec
• Patients with a history of other malignancies unless having undergone definitive treatment more than 5 years prior to entry into the study and without evidence of recurrent malignant disease, excluding patients with basal cell carcinoma of the skin; superficial carcinoma of the bladder; carcinoma of the prostate with a current PSA < 0.1 ng/ml; or cervical intraepithelial neoplasia
• Patients with a history of significant cardiovascular, neurological, endocrine, gastrointestinal, respiratory or inflammatory illness that could preclude their participation in the trial, pose an undue medical hazard or interfere with the interpretation of the trial results, including, but not limited to, patients with congestive heart failure (NYHA Class 3 or 4); unstable angina; cardiac arrhythmia; recent (within the preceding 6 months) myocardial infarction or stroke; hypertension requiring > 2 medications for adequate control; diabetes mellitus with > 2 episodes of ketoacidosis in the preceding 12 months