To evaluate the long-term safety and tolerability of ublituximab (UTX) treatment in patients with relapsing forms of multiple sclerosis (RMS) enrolled in the Open Label Extension (OLE) of a phase 2 trial.

UTX is a novel mAb targeting a unique epitope on the CD20 antigen and glyco-engineered for enhanced B-cell targeting through antibody-dependent cellular cytotoxicity (ADCC). Two Phase III trials, ULTIMATE I and II, are fully enrolled and are investigating the efficacy and safety of UTX in RMS.

TG1101-RMS201 was a 52-week, phase 2, placebo-controlled, multicenter study of UTX in RMS. Subjects who completed RMS201 were eligible to continue treatment in the OLE, receiving one-hour 450mg UTX infusions every 24 weeks.

RMS201 enrolled 48 subjects and the primary endpoint was to evaluate B-cell depletion.  Median B-cell depletion of >99% was observed at Week 4 and maintained at Week 48. At Week 48, key observations included: 100% reduction in T1-Gd enhancing lesions; 10.6% mean decrease in T2 lesion volume; 93% of subjects relapse free, and an annualized relapse rate (ARR) of 0.07. Ublituximab was well tolerated; the most common adverse events was infusion related reactions (all grade 1-2). No discontinuations due to AEs were reported. Ublituximab continues to be well tolerated, with a median duration of follow-up of 124.7 weeks, no drug related discontinuations and only one AE deemed at least possibly related to ublituximab that occurred in more than 1 patient, which was infusion related reaction (IRR) all grade 1 or 2 in severity. At the time of presentation, long-term safety information will be presented for all patients on the OLE. 

The Phase 2 OLE data support that ublituximab continues to be safe, well tolerated and effective with one-hour infusions. These results support the ongoing Phase 3 ULTIMATE program in RMS.