There is no difference with respect to efficacy between ofatumumab in combination with cisplatin, cytarabine, and dexamethasone (O-DHAP) and rituximab plus DHAP (R-DHAP) as salvage therapy in patients with relapsed or refractory diffuse large B cell lymphoma (DLBCL), according to a study published in the Journal of Clinical Oncology.1
The efficacy of rituximab combined with salvage chemotherapy in the second-line setting has decreased as rituximab-based regimens have become standard first-line treatment in CD20 positive DLBCL. Therefore, there is a growing need for new therapies in patients progressing or relapsing after first-line rituximab-based therapy.
Replacing rituximab with ofatumumab in the second-line setting, following progression or relapse after first-line rituximab-containing regimens, may overcome relative or complete rituximab resistance, thereby improving response rates, the ability to proceed to consolidative autologous hematopoietic cell transplantation, and overall survival.
To compare the efficacy of O-DHAP with R-DHAP as salvage treatment, followed by autologous hematopoietic cell transplantation, researchers enrolled 447 patients with CD20-positive DLBCL who had experienced their first relapse or who were refractory to first-line therapy with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP).
Participants were randomly assigned 1:1 to receive a total of 4 infusions of either ofatumumab or rituximab with DHAP. Patients who experienced a response after 2 cycles of therapy received a third cycle followed by high dose therapy and autologous stem cell transplantation.
Results showed that there were no significant differences in progression-free survival, event-free survival, or overall survival between the 2 treatment arms.
Researchers found that 24% of patients who received ofatumumab were free of progression or death at 2 years vs 26% of those who received rituximab (hazard ratio [HR], 1.12; 95% CI, 0.89-1.42; P =.33); 2-year overall survival was 41% and 38%, respectively (HR, 0.90; P =.38).
The rate of adverse events leading to permanent treatment discontinuation was similar between the 2 groups, but more patients receiving ofatumumab required dose interruptions or treatment delays, primarily because of a higher incidence of rash, urticaria, infusion-related reactions, and pruritus during the first infusion of ofatumumab.
1. van Imhoff GW, McMillan A, Matasar MJ, et al. Ofatumumab versus rituximab salvage chemoimmunotherapy in relapsed or refractory diffuse large b-cell lymphoma: The ORCHARRD study. J Clin Oncol. 2016 Dec 28. doi: 10.1200/JCO.2016.69.0198. [Epub ahead of print]