Treatment of relapsed or refractory non-hodgkin lymphoma with the oral isotype-selective histone deacetylase inhibitor MGCD0103: Interim results from a phase II study

8528 Background: MGCD0103 is an orally available selective inhibitor of histone deacetylases (HDACs) with significant biological activity in preclinical models of both solid tumors and hematopoietic cancers. Methods: Open-label, Phase II trial in adults (Trial 008) with relapsed or refractory diffuse large B-cell lymphoma (DLBCL) or follicular lymphoma (FL). Eligibility included: ≥1 site of measurable disease (≥2.0 cm), ECOG 0 or 1. MGCD0103 was given 3x/week starting at 110 mg; after 32 patients (pts) the starting dose was reduced to 85 mg. Tumor responses were determined every 2 cycles. PK was evaluated on Day 1, Cycle 1. Results: 50 pts received treatment; 33 DLBCL and 17 FL (median age [range], 61.5 years [32−80]; male, n=27; prior rituximab therapy: 96%; prior stem cell transplant: 33%). The response rate in pts with DLBCL met the protocol defined criteria for expansion beyond 21 pts, and enrollment of this cohort is now complete. Of 17 DLBCL pts with tumor reassessed by CT, most had tumor reduction,...