Amgen added another notch on its biosimilar belt last week, receiving approval from the Food and Drug Administration (FDA) to market ABP798, its biosimilar version of Rituxan®. The drug, dubbed Riabni™ (rituximab-arrx), is the third biosimilar rituximab available in the US.
It was approved for adult patients with the following indications:
- Non-Hodgkin’s lymphoma
- Chronic lymphocytic leukemia
- Granulomatosis with polyangiitis (Wegner’s granulomatosis)
- Microscopic polyangiitis

Riabni’s slate of indications is very similar to those approved for its biosimilar competitors Truxima® and Ruxience®. Unlike its biosimilar competitors, the reference product is also approved for use in patients with rheumatoid arthritis.
Amgen announced that it will begin marketing Riabni in January 2021, at nearly a 24% discount to the wholesale acquisition cost (WAC) of the reference product Rituxan ($716.80 per 100-mg vial or $3,584 per 500-mg vial). It is also approximately 17% below the current average selling price (ASP) of the originator. Amgen noted that the WAC for Riabni is equal to that for Ruxience and 15% lower than that for its Truxima, the two biosimilar competitors in the market. Average selling prices for the two previously launched biosimilars are not yet available.
Riabni is the fifth biosimilar approval for Amgen in the US, with three marketed (its biosimilar version of infliximab [Avasola®] adalimumab [Amjevita®] have not yet launched). The company noted in its press release that it has 10 approved and investigational biosimilars in its portfolio at the present time.