Role of CD20 monoclonal antibodies in previously untreated chronic lymphocytic leukemia

A phase 1/2 trial of ublituximab, a novel anti-CD20 monoclonal antibody, in patients with B-cell non-Hodgkin lymphoma or chronic lymphocytic leukaemia previously exposed to rituximab

This phase 1/2 study evaluated the safety, pharmacokinetic behavior and anti‐tumour activity of ublituximab, a unique type I, chimeric, glycoengineered anti‐CD20 monoclonal antibody, in rituximab‐relapsed or ‐refractory patients with B‐cell non‐Hodgkin lymphoma (B‐NHL) or chronic lymphocytic leukaemia (CLL). Induction therapy (doses of 450–1200 mg) consisted of 4 weekly infusions in cycle 1 for NHL and 3 weekly infusions in cycles 1 and 2 for CLL. Patients received ublituximab maintenance monthly during cycles 3–5, then once every 3 months for up to 2 years. Enrolled patients with B‐NHL (n = 27) and CLL (n = 8) had a median of 3 prior therapies. No dose‐limiting toxicities or unexpected adverse events (AEs) occurred. The most common AEs were infusion‐related reactions (40%; grade 3/4, 0%); fatigue (37%; grade 3/4, 3%); pyrexia (29%; grade 3/4, 0%); and diarrhoea (26%; grade 3/4, 0%). Common haematological AEs were neutropenia (14%; grade 3/4, 14%) and anaemia (11%; grade 3/4, 6%). The overall response rate for evaluable patients (n = 31) was 45% (13% complete responses, 32% partial responses). Median duration of response and progression‐free survival were 9·2 months and 7·7 months, respectively. Ublituximab was well‐tolerated and efficacious in a heterogeneous and highly rituximab‐pre‐treated patient population.

Changes in the apoptotic gene expression profile in CLL patients treated with rituximab combined with cladribine and cyclophosphamide-preliminary results

The study was aimed to investigate modifications of apoptotic gene expression profile by microarray technique in 10 patients with chronic lymphocytic leukemia by treatment with rituximab, cladribine and cyclophosphamide (RCC) according to IGHV mutational status. The TaqMan Low Density Array for 96 gene transcripts was used. Those modifications followed two distinctive patterns largely overlapping the IGHV mutational status. In the IGHV-mutated group, the expression of many proapoptotic genes increased after treatment as compared to initial value. Our results suggest that RCC drugs may act through influence on the expression of some apoptosis-involved genes dependently on the IGVH mutational status.

The emerging role of ofatumumab in the treatment of chronic lymphocytic leukemia

The treatment of chronic lymphocytic leukemia (CLL) has evolved over the past decade. Our better understanding of disease biology and risk stratification has allowed delivering more effective therapies. In fact, front-line chemoimmunotherapy has demonstrated improvement in overall survival when compared to chemotherapy in randomized studies. Yet, treatment of relapsed CLL remains challenging and few agents are effective in that setting. Ofatumumab (Ofa) is a humanized monoclonal antibody targeted against CD20 with demonstrable activity in rituximab-resistant CLL cell lines. This agent was recently approved for the treatment of relapsed/refractory CLL patients who have failed fludarabine and alemtuzumab. In this review, we provide a historical perspective on approaches to CLL as front-line and in the relapsed setting. We further summarize novel anti-CD20 antibodies with specific emphasis on ofa. We review studies that led to ofatumumab's approval including pre-clinical data, trials using ofa in combination therapies, and adverse events/toxicities reported with this agent.