Stepping-up dosing approach for ofatumumab is safe and reduces administration time

This study tested the safety of ofatumumab (Arzerra) when administered using a stepping-up dosing approach. The approach was found to be safe and well tolerated.

Chemotherapy and immunotherapy are usually the first-line treatment of CLL. In cases of disease relapse, alternative treatment options are usually explored. This is because many patients develop a resistance to standard therapy over time.

Monoclonal antibody therapy is a treatment that uses antibodies that attach to cancer cells, killing them or making them unable to grow. Ofatumumab is a type of monoclonal antibody therapy (for the CD20 protein) currently being developed for CLL. Ofatumumab is given as an injection or infusion into the vein that typically takes about 4 hours. Studies using other monoclonal antibodies have shown that gradually increasing the dose and giving a second larger dose within a few days, if tolerated, allows for a faster administration of the drug. Whether the rapid-infusion approach is safe for ofatumumab has not been fully studied.

The aim of this study was to test the rapid-infusion approach for ofatumumab.

34 patients with previously treated CLL were included. All patients received ofatumumab using the rapid-infusion approach.

Ofatumumab was started on week 1 day 1 at a dose of 3.6 mg/hour and doubling every 30 minutes until 240 mg/hour was reached. If the first dose was tolerated, the second dose was given two days later, starting at 50 mg/hour and doubling every 30 minutes until 800 mg/hour was reached. The third dose was given on week 2 day 1 at 800 mg/hour over the first 30 minutes and, if tolerated, at 1,068 mg/hour over the next 90 minutes. The goal infusion time was 120 minutes. Subsequent infusions were administered weekly in the same manner for 8 weeks, and then monthly for 4 months.

Most infusion-related reactions occurred during the first and second infusion. 62% of patients experienced a reaction following the first infusion. It was 12% for the second infusion and decreased to 3% for the third infusion.

Serious reactions included shortness of breath (in 1 patient) and hives (in 1 patient). Other side effects included low white and red blood cell counts and injection site reaction.

97% of patients completed the third infusion. Of these, 87% completed the third infusion within the 2-hour goal infusion time. Only 1 patient had an infusion-related reaction during or after the third infusion.

This study concluded that the rapid-infusion of ofatumumab is safe and well tolerated.

Further studies are needed to confirm these results.