The US Food and Drug Administration (FDA) has granted orphan drug designation to CUDC-907 for the treatment of diffuse large B-cell lymphoma (DLBCL).
CUDC-907 is an oral, dual inhibitor of histone deacetylase and phosphoinositide 3-kinase enzymes. It is currently under investigation in phase 1 trials in patients with relapsed or refractory lymphomas, multiple myeloma, and advanced/relapsed solid tumors.
The FDA grants orphan status to products intended for treating diseases that affect fewer than 200,000 people in the US. Orphan designation qualifies the drug’s developer—in this case, Curis, Inc.—with incentives such as tax credits for qualified trials, the ability to apply for annual grant funding, and 7 years of market exclusivity once the drug is approved.
Phase 1 data
At the 2013 ASH Annual Meeting, researchers presented interim data from a phase 1, dose-escalation trial of CUDC-907 in patients with advanced lymphoma or multiple myeloma.
Thirteen patients had received CUDC-907 on either once-daily (QD) or twice-weekly (BIW) schedules at doses of 30 mg QD (n=7), 60 mg QD (n=3), or 60 mg BIW (n=3).
Dose-limiting toxicities (DLTs) of grade 3 diarrhea and grade 4 hyperglycemia were reported in 1 patient at the 60 mg QD dose. The most frequent grade 3 or 4 adverse events reported in 2 or more patients included thrombocytopenia, diarrhea, and neutropenia. Tolerability limited the ability to further dose escalate using the QD schedule.
No DLTs or dose interruptions were reported for patients enrolled on the BIW schedule. So dose escalation is ongoing with the BIW schedule as well as a separate, thrice-weekly treatment schedule.
Of the 13 patients treated, 11 were evaluable for response. One patient with mixed follicular lymphoma/DLBCL achieved a partial response, with a 70% reduction in a single target lesion observed at the 30 mg QD dose level.
Seven other patients met criteria for stable disease, including 4 with stable disease lasting at least 4 cycles of treatment.
Following the ASH presentation, Curis reported additional data from a subset of patients that suggest CUDC-907 has antitumor activity in patients with DLBCL.
For the November 10, 2014, data cutoff period, 8 patients with DLBCL were evaluable. One of these patients had a complete response, 2 had a partial response (tumor shrinkage greater than 50%), and 4 had tumor shrinkage ranging from 5% to 46%.
The dose-escalation stage of the trial is nearing completion, and Curis expects to present full data this year. Curis has also initiated an expansion cohort to further evaluate CUDC-907 in patients with DLBCL or multiple myeloma at the recommended phase 2 dose.
