Clinical Data Four patients discontinued prior to the first efficacy assessment and were not evaluable for response (2 for AEs not related to study drug; 1 for a serious AE [pneumonia]; and 1 patient withdrew consent). All 35 patients were evaluated for safety.At the end of the study, 21/35 (60%) patients had discontinued treatment for progression, while 8/35 (23%) patients stopped treatment for other reasons [AE/serious AE (n = 3); withdrawal of consent (n = 1); or investigator/patient decision (n = 4)]. The remaining 6/35 (17%) completed all treatment.


All 35 patients experienced ≥1 AE, with 17 (49%) reporting at least 1 grade 3/4 AE. Seventeen patients (49%) required ≥1 dose interruption, of which 11 were for IRRs. IRRs occurred in 14 (40%) patients (Table 3) and were more prevalent among patients with CLL. The majority of IRRs occurred on C1D1, with only 5 occurring on subsequent cycles. No episodes of grade ≥3 IRR were reported. All IRRs were manageable with infusion interruptions, and all patients recovered without repercussion.


The best ORR to ublituximab among 31 patients evaluable for efficacy was 45% (Fig 2A). Forty-five per cent of patients had stable disease (SD), and 10% experienced progressive disease (PD) at the first efficacy assessment. Five patients experienced improvement in their response during the maintenance phase as follows: three patients (one patient each with CLL, marginal zone lymphoma [MZL] and FL) improved from SD to partial response (PR); while two patients (one patient each with FL and MZL) improved their response from PR to complete response (CR). Only 15 (48%) patients progressed during the maintenance phase, supporting the potential merits of protracted dosing in this heavily treated population.