Phase 1 and pharmacological trial of OPB-31121, a signal transducer and activator of transcription-3 inhibitor, in patients with advanced hepatocellular carcinoma.

AIM: To evaluate the safety, pharmacokinetics and antitumor activity of OPB-31121, a signal transducer and activator of transcription-3 inhibitor, in patients with advanced hepatocellular carcinoma (HCC).
METHODS: HCC patients of Child-Pugh A or B who progressed on, or were intolerant to, sorafenib were eligible for this phase 1 trial. We used a standard 3 + 3 dose-escalation design with a 28-day cycle at dose levels of 50, 100, 200 and 400 mg/day. Tumor responses were assessed using the modified Response Evaluation Criteria in Solid Tumors.
RESULTS: Twenty-four patients were enrolled, of whom 23 received OPB-31121 (20 males; median age, 65 years). The most common adverse drug reactions were nausea (87.0%), vomiting (82.6%), diarrhea (69.6%), fatigue/malaise (52.2%), anorexia (47.8%) and peripheral sensory neuropathy (26.1%). The recommended dose for OPB-31121 was determined to be 200 mg. Six patients had stable disease for 8 weeks or more, resulting in disease control rates of 25.0-42.9%. In the 200-mg dose cohort, three of seven patients had stable disease and a median time to progression of 61.0 days. The maximum concentration and area under the plasma concentration-time curve of OPB-31121 were dose proportional.
CONCLUSION: OPB-31121 demonstrated insufficient antitumor activity for HCC. Furthermore, peripheral nervous system-related toxicities may negatively affect long-term administration of OPB-31121. Therefore, it was deemed difficult to continue the clinical development of OPB-31121 for treating advanced HCC and further investigation is expected in the agent with favorable profile in this category.