CD47 blockade by Hu5F9-G4 and rituximab in non-Hodgkin's lymphoma

Investigators tested the safety and efficacy of the Hu5F9-G4 (5F9) antibody, a macrophage checkpoint inhibitor, as a potential intervention for patients with relapsed or refractory non-Hodgkin's lymphoma. The research involved 22 patients who had poor response to a median of four previous therapies.

Investigators tested the safety and efficacy of the Hu5F9-G4 (5F9) antibody, a macrophage checkpoint inhibitor, as a potential intervention for patients with relapsed or refractory non-Hodgkin's lymphoma. The research involved 22 patients who had poor response to a median of four previous therapies. Most of the participants also presented with disease that was refractory to rituximab. Approximately one-half of them, however, had partial or complete response when rituximab was combined with I.V. 5F9 at a dose of 30 mg per kilogram. The benefit was greater for the seven patients with follicular lymphoma vs. the 15 patients with large B-cell lymphoma. At followup of roughly 6–8 months, 91% of the responses were still ongoing, with no major safety concerns. The researchers determined that 5F9, which blocks CD47 that induces tumor-cell phagocytosis, synergizes with rituximab to eliminate B-cell non-Hodgkin's lymphoma cells. The combination has promise for patients with aggressive or stubborn lymphoma, they concluded.