Celltrion’s Rituxan biosimilar wins rare disease nod as Pfizer, Amgen land same-day OKs

Celltrion just checked off a major box in its race to match Roche’s Rituxan (rituximab).

On Wednesday U.S. time, the FDA approved Truxima for use in moderate to severe pemphigus vulgaris (PV), a rare autoimmune blistering disease, granting the Korean biosimilar maker its fifth adult indication for the CD20-targeting therapy. 

The approval brings Truxima nearly in line with Rituxan’s label, with only pediatric lymphoma and leukemia still out of reach.

Celltrion filed the supplemental biologics license application (sBLA) in November 2024. With this latest addition, Truxima now covers non-Hodgkin’s lymphoma, chronic lymphocytic leukemia (CLL), rheumatoid arthritis (RA), granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), and PV.

But Celltrion wasn’t the only winner. Pfizer and Amgen also scored approvals the same day for their Rituxan biosimilars, Ruxience and Riabni, respectively, in the PV indication.

Still, label gaps remain. Ruxience continues to trail behind, missing both CLL and RA, making it the only biosimilar without full adult coverage. Riabni, by contrast, now mirrors Rituxan’s label across all approved uses, including pediatric patients with GPA and MPA. Truxima, while still limited to adult settings, has now closed every major non-pediatric gap.

Launched in the U.S. in late 2019, Truxima has maintained a 30 percent market share, with Celltrion expected to pursue further gains following its label expansion.

First approved in Europe in 2017, Truxima was the world’s first oncology biosimilar of Rituxan and marked Celltrion’s second biosimilar after Remsima. 

As of 2024, the company reported a 30 percent market share in Europe as well, according to its February earnings report.

In the autoimmune setting, Truxima and Ruxience have historically lagged behind Rituxan and Riabni. Both remain limited to adult GPA and MPA use, while Rituxan and Riabni hold approvals for children as young as two.