Mocetinostat for relapsed classical Hodgkin's lymphoma: an open-label, single-arm, phase 2 trial.

backgroundThe prognosis of patients with relapsed Hodgkin's lymphoma, especially those who relapse after stem-cell transplantation, is poor, and the development of new agents for this patient population is an unmet medical need. We tested the safety and efficacy of mocetinostat, an oral isotype-selective histone deacetylase inhibitor, in patients with relapsed classical Hodgkin's lymphoma.

methodsPatients with relapsed or refractory classical Hodgkin's lymphoma aged 18 years or older were treated with mocetinostat administered orally three times per week, in 28-day cycles. Two doses were assessed (85 mg and 110 mg). Patients were treated until disease progression or prohibitive toxicity. The primary outcome was disease control rate, defined as complete response, partial response, or stable disease (for at least six cycles), analysed by intention to treat. This trial has been completed and is registered with ClinicalTrials.gov, number NCT00358982.

findings51 patients were enrolled. Initially, 23 patients were enrolled in the 110 mg cohort. Subsequently, because toxicity-related dose reductions were necessary in the 110 mg cohort, we treated 28 additional patients with a dose of 85 mg. On the basis of intent-to-treat analysis, the disease control rate was 35% (eight of 23 patients) in the 110 mg group and 25% (seven of 28) in the 85 mg group. 12 patients (24%) discontinued treatment because of adverse events, nine (32%) in the 85 mg cohort and three (13%) in the 110 mg cohort. The most frequent treatment-related grade 3 and 4 adverse events were neutropenia (four patients [17%] in the 110 mg group, three [11%] in the 85 mg group); fatigue (five patients [22%] in the 110 mg group, three [11%] in the 85 mg group); and pneumonia (four patients [17%] in the 110 mg group, two [7%] in the 85 mg group). Four patients, all in the 110 mg cohort, died during the study, of which two might have been related to treatment.

interpretationMocetinostat, 85 mg three times per week, has promising single-agent clinical activity with manageable toxicity in patients with relapsed classical Hodgkin's lymphoma.

fundingMethylGene Inc, Montreal, Canada; Celgene Corporation, Summit, NJ, USA; Tufts Medical Center, Boston, MA, USA.