December 17, 2020
The U.S. FDA has approved Riabni™ (rituximab-arrx), manufactured by Amgen, as the third biosimilar for Genentech’s Rituxan® (rituximab). Riabni is indicated to treat certain adults who have non-Hodgkin lymphoma (NHL), chronic lymphocytic leukemia (CLL), granulomatosis with polyangiitis (GPA) or microscopic polyangiitis (MPA).
Based on the totality of evidence, including a clinical study, the U.S. FDA found Riabni to be highly similar to Rituxan and to have similar safety and efficacy. However, unlike generic drugs, biosimilars cannot be automatically interchanged with the reference product. Switching a patient from Rituxan to Riabni would require a new prescription from the patient’s physician.
Recommended dosing with Riabni is based on the condition being treated. A black box warning cautions that there is a risk of fatal infusion-related reactions within 24 hours of administration with all rituximab products, as well as severe and potentially fatal mucocutaneous reactions (reactions affecting the skin and mucous membranes), and potentially life-threatening progressive multifocal leukoencephalopathy (a rare brain infection). The black box warning also advises there is a risk of potentially fatal hepatitis B virus (HBV) reactivation in patients infected with HBV.
Amgen has launched Riabni at a wholesale acquisition cost (WAC) that is 23.7% lower than the cost of Rituxan, 15.2% less than competing biosimilar Truxima® (rituximab-abbs – Teva), and equivalent to the WAC for competing biosimilar Ruxience® (rituximab-pvvr – Pfizer).