Comparing ublituximab plus ibrutinib versus ibrutinib alone for patients with relapsed or refractory high-risk chronic lymphocytic leukemia

This study investigated the safety and effectiveness of adding ublituximab (TG-1101) to ibrutinib (Imbruvica) treatment for patients with relapsed or refractory (r/r) chronic lymphocytic leukemia (CLL). The data showed that adding ublituximab to ibrutinib significantly improved the overall response rate compared to ibrutinib alone with similar side effects in these patients.

Chronic lymphocytic leukemia (CLL) is a type of cancer in which the bone marrow makes too many lymphocytes (a type of white blood cell). A high number of patients with CLL experience relapse (worsening of the disease) or refractory (not responsive to the treatment) disease despite treatment. Highly effective targeted therapies have been developed for CLL as it can be challenging to treat.

Ibrutinib is a targeted therapy known as a kinase inhibitor. It has shown good outcomes when given alone and has been approved for the treatment of CLL. Ublituximab is an antibody (immunotherapy) that uses the body’s own immune system to identify and kill cancerous B-cells (a type of white blood cell). Whether the addition of ublituximab to ibrutinib monotherapy improves outcomes in patients with r/r CLL is not known.

This study involved 126 patients with r/r CLL. Patients were randomly assigned into 2 groups. Group 1 included 64 patients who received ublituximab plus ibrutinib. Group 2 included 62 patients who received ibrutinib alone. The average follow-up time was 41.6 months.

The overall response rate (ORR; the partial or complete disappearance of the cancer) was 83% in group 1 compared to 65% in group 2. Patients in group 1 were 54% more likely to have a longer survival without cancer worsening compared to group 2.

Severe side effects were reported in 76% of group 1 and 83% of group 2. The most common side effects were pneumonia, a low number of white blood cells, and diarrhea.

This study concluded that adding ublituximab to ibrutinib significantly improved the overall response rate compared to ibrutinib alone with manageable side effects for the treatment of patients with r/r CLL. The authors suggested that ublituximab could be added to ibrutinib as a treatment option.

This study was sponsored by TG Therapeutics, the manufacturers of ublituximab.