Rituximab Combination Has Positive Activity in Non-Hodgkin Lymphoma

Hu5F9, an immune checkpoint inhibitor blocking CD47, has showed promise in working together with rituximab to eliminate non-Hodgkin lymphoma cells. A recent study looked to evaluate the combination therapy in a clinical setting.

Researchers conducted a phase 1B study that enrolled 22 patients with relapsed or refractory Hodgkin lymphoma. Hu5F9 was administered intravenously at a priming dose of 1 mg per kg of body weight, with a weekly maintenance dose of 10 mg to 30 mg per kg together with rituximab in order to allow for the evaluation of safety and efficacy in suggesting a phase 2 dose.

Of the 22 patients enrolled, 15 had diffuse large B-cell lymphoma (DLBCL) and 7 had follicular lymphoma. Patients had received a median of 4 (range, 2-10) prior therapies, and 95% of the patients had disease that was refractory to rituximab. The most common adverse events seen in the trial were anemia and infusion-related reactions.

In total, 50% of patients demonstrated an objective response to the therapy, with 36% experiencing a complete response. The rates of objective response and complete response were 40% and 33%, respectively, among patients with DLBCL and 71% and 43%, respectively, among patients with follicular lymphoma. Additionally, at a median follow-up of 6.2 months among patients with DLBCL and 8.1 months in patients with follicular lymphoma, researchers noted that 91% of the responses were ongoing.

Overall, the study authors reported that “The macrophage checkpoint inhibitor [Hu5F9] combined with rituximab showed promising activity in patients with aggressive and indolent lymphoma.” Furthermore, the authors found that there were no clinically significant safety events demonstrated in the trial.

Reference

Advani R, Flinn I, Popplewell L, et al. CD47 blockade by Hu5f9-G4 and rituximab in non-Hodgkin’s lymphoma. N Engl J Med. 2018;379(18):1711-1721. doi: 10.1056/NEJMoa1807315.