FDA Clears Rituximab Biosimilar, Expanding Options for B-Cell Malignancies

The FDA has approved a biosimilar for rituximab (Rituxan) developed by Dr. Reddy's Laboratories, expanding the roster of CD20-directed therapies available for treatment of select B-cell malignancies and autoimmune diseases in the United States.¹

The regulatory decision was supported by totality of evidence encompassing analytical, nonclinical, and clinical data demonstrating that the biosimilar is highly similar to the reference product, with no clinically meaningful differences.

"This [biosimilar] reinforces our commitment to expanding patient access to high-quality, affordable biologic medicines in the US market," Sang-Jin Pak, MD, president of biopharma at Fresenius Kabi, stated in a news release.

Biosimilars to rituximab have been available in the United States for several years, and additional entrants have generally been associated with increased competition in the CD20-targeted therapy market. The addition of another rituximab biosimilar may factor into formulary and purchasing decisions, particularly as institutions and practices weigh acquisition cost alongside continuity of supply.

About Rituximab and Existing Indications

Rituximab is a monoclonal antibody that binds the CD20 antigen expressed on B lymphocytes, triggering B-cell depletion through multiple immune-mediated mechanisms. First approved by the FDA in 1997 for treatment of non-Hodgkin lymphoma, its clinical use has since expanded to chronic lymphocytic leukemia and other autoimmune diseases.²

Safety Profile

The safety profile of the biosimilar is consistent across the reference product and previously approved rituximab biosimilars marketed in the United States. Rituximab products carry a boxed warning for fatal infusion-related reactions, severe mucocutaneous reactions, hepatitis B virus reactivation, and progressive multifocal leukoencephalopathy.³ Serious infections and other significant adverse reactions may also occur with treatment.

REFERENCES

1. Fresenius Announces FDA Approval of Rituximab Biosimilar for the U.S. Market. News release. Fresenius Kabi. August 3, 2026. Accessed August 4, 2026. https://tinyurl.com/2p9kmhyu

2. Delate T, Hansen ML, Gutierrez AC, Le KN. Indications for Rituximab Use in an Integrated Health Care Delivery System. J Manag Care Spec Pharm. 2020;26(7):832-838. doi:10.18553/jmcp.2020.26.7.832

3. Rituxan - Prescribing information. Genentech. Updated December 2021. Accessed August 4, 2026. https://tinyurl.com/4ekakcmk